White Balance can be adjusted to correctly display white and other colours according to different lighting conditions, either as set on camera at the time of image capture, or from other settings if the original white balance was incorrect.

Exposure compensation can be used to adjust underexposure or overexposure in the original image. Additional tuning can be acheived by adjusting brightness and shadow settings, while Saturation settings can be used to increase or decrease colours. The effect of any adjustments can be seen in the preview image on the left side of the dialog box. When everything is satisfactory, click OK to convert the RAW file.

Editing 48 bit Images
48 bit images can only be edited with a subset of PI 11 tools, but these include the more important ones for photo editing, such as Levels, Curves, Colour Adjustment, Unsharp Mask, Crop and Gaussian Blur among others.

Saving 48 bit Images
48 bit images can only be saved as TIFF or UFO files (the latter used for images with 2 or more layer objects), and an image saved as 48 bit TIFF will be approximately twice the megabyte size of a 24 bit image. The file size will be dependent on the size of the original RAW file, but an 8 megapixel camera image can produce a 48 megabyte TIFF file.

Comparison of 24 bit and 48 bit Images
The histograms below show a 24 bit and 48 bit file following conversion from RAW, and minor editing using the Levels tool. The histogram of the 24 bit image displays the 'picket line' effect, indicating some loss of colour from the image, frequently seen after editing tools have been used on a photo, while the 48 bit histogram retains its colour distribution. Whether this difference can be seen by the human eye, either on a monitor or print, is perhaps debatable, but the histograms below do suggest that 48 bit images are probably the best option if maximum quality is required from an image.

24 bit image histogram

48 bit image histogram

HDR image left, original images above.

To use PhotoImpact's HDR tool, first open the images you wish to use. A minimum of 2 images are needed, but you should get better results if 3 or 4 are used. As mentioned above, images should ideally be taken with the camera on a tripod to ensure composition is identical in all cases. When the images are open, select High Dynamic Range from the Photo menu on the main toolbar (see right).

The HDR dialog box deals with three tasks, composition, optimization and operations. In the composition task (see screen below), simply select the camera brand used to take the photos, in this example, Canon, then click the button in the bottom right hand corner (circled red) to generate the HDR image.

If your camera brand does not appear in the drop down list, you can still use an option in the list to see the results. Alternatively, you can create your own camera curve profile by using 3 to 5 images and checking the 'auto generate camera curve' button instead. If this produces suitable output, you can save the profile for future use.

When creating your own profile, you need to specify the 'F stop' (aperture) interval used by the camera to take the images. If the images still retain their EXIF data (the digital cameras record of settings used, eg shutter speed, aperture) the F stop can be calculated automatically, otherwise this needs to be set manually in the dialog box. Typical examples could be half or one stop intervals between each images exposure. If you are unfamiliar with camera exposure settings, there are many introductory photography books available with information on this subject.

After creating the initial HDR image, further tonal adjustments can be done on the highlight, midtone and shadow areas within the Optimization screen (see below) by adjusting the appropriate sliders (note: the final HDR image can also be edited with PhotoImpact tools such as Levels or Curves if preferred).

The Operations stage allows basic editing tasks to be completed if required, namely rotating, resizing or cropping the image, although these tasks can also be completed with PhotoImpacts standard editing tools. If the Resize option is used to change the image dimensions, ensure the padlock (highlighted red, right) is checked to retain the images height and width ratio. When all tasks are complete, click OK to create the final HDR image and save to file.

A comparison of the HDR image with an edited version of one of the original images is shown below. The original image (shown left), exposed for mid tone areas, was edited using 'Curves', previously known as Tone Map in earlier versions of PhotoImpact. Although this image has produced a quite acceptable result, the tonal range and detail in the HDR image (shown right) is better.

- the horizon is sloping towards the left hand side of the photo because the camera was not held straight at the point of capture.
- the overall tonality is rather flat and lacking contrast, with shadow areas too bright.
- finally, the foreground area would look better cropped slightly to emphasise the more interesting sea, lighthouse and sky areas of the photo.

All these faults can be corrected easily with PhotoImpact, as seen by the final edited image (below).

1-Adjusting a sloping horizon

A sloping horizon can be corrected with the Transform Tool (indicated with cursor pointer below), which can be used for a variety of amendments including perspective, distort and slant.

To adjust sloping horizons in landscape photos, a quick method is the Rotate With A Horizontal Line 0ption (see highlighted Rotate Method icon in image right). When this method is selected, a horizontal line appears in the centre of the image. Use the computer mouse to move the line to the desired location and angle by clicking on and dragging the end points of the horizontal line. When in position, double click the mouse and PhotoImpact rotates the image to the same angle as the line. Its best to make adjustments like Transform in one go to minimise loss of image quality arising from multiple attempts to complete the task. If your first attempt is incorrect, cancel it (right mouse click>Undo) and do the adjustment again after changing the number in the Rotate By Degree setting.

Adjusting a sloping horizon - Alternative Method

Sloping horizons can also be straightened using the Rotate By Degree method. Enter the estimated number of degrees in the box (see right) that the image needs to be rotated, then click the left or right rotate icon and PhotoImpact rotates the image accordingly.

When using the Rotate by Degree method, its often helpful to switch on Gridlines (select View on the Standard Toolbar, then Grid). This displays a set of vertical and horizontal lines over the image which can be used to visually assess if your adjustment is correct. If necessary, Gridline spacing, colour and display type can be adjusted (click File> Preferences>General>Guidelines and Grid, then alter the settings).

2-Using The Crop Tool

The Crop Tool is used for changing the size or shape of an image, in this example, fine tuning the image composition by removing some of the foreground area. After selecting the Crop Tool (highlighted left), drag the mouse across the image to select the cropped size. The area shown in red (see below) will be cropped. Use the mouse to move and fine tune the cropping area handles into the preferred positions, then click inside the cropping lines to perform the action.

The colour and transparency of the 'shielded' area can be changed if preferred. For example, if your photo is predominantly red, you could change the colour of the shielded area to green, or some other colour that contrasts well with your photo. To change shield colour, click the coloured square (see below) on the Crop Tool attribute bar and select a suitable colour from the dialog box that opens.

3-Adjusting Highlights, Midtones and Shadows

The final stage in this tutorial involves adjustments using Levels. This tool enables amendments to three tonal parts of an image, namely highlights, midtones and shadow areas. When the Levels dialog box is opened (select Format>Levels) a histogram is shown which displays the distribution of tones in an image as a 256 step greyscale from pure black to pure white (see dialog box below).

The horizontal greyscale (Input Level) is used to adjust contrast by moving the black point and white point sliders, while the grey point slider adjusts midtones. If the histogram display falls away before reaching the black and white point sliders, move the sliders in towards the edge of the histogram to reset the images black and white points.

In the example shown right, the black point has been changed from 0 (zero) to 5, which is a little lighter than solid black, while the white point has been changed from 255 (pure white) to 245. The greypoint slider has also been changed, from a value of 1 to 0.84 to darken midtone areas. Moving the greypoint slider towards the white point slider darkens midtones, while moving it to the black point slider lightens midtones. If the Preview check box is clicked, any adjustments made will show in the thumbnail image in the dialog box. Alternatively, you can preview the effect on your full size image by clicking the Preview button on the dialog box.

In addition to adjusting highlights, midtones and shadows on the Master channel, Levels adjustments can also be made to the Red, Green and Blue (RGB) image channels. The general procedure is the same as adjusting the Master channel. First select the channel you wish to adust from the pull down Channel menu, then move the sliders as required. Adjusting both the Master and RGB channels usually produces an image that has a good tonal range without any obvious colour cast.

Many photos will produce a histogram similar in shape to the one shown above, but some photographs, usually referred to as 'high key' (comprising mainly light tones) and 'low key' (comprising mainly dark tones) will have a very different distribution. The Levels Tool can still be used to adjust these types of images where required though.

The vertical greyscale (Output Level) is used to adjust overall brightness, but for many images this can usually be left at the default settings. This also works on a 256 step greyscale, but has just two sliders instead of three.

The Levels Tool also has two 'auto' options (Stretch and Equalise) which can be used to adjust image tones. These can be tried to see if they give quick fixes, but you will probably get better results by adjusting sliders as discussed above.

Note : Although Levels was only introduced with version 8 of PhotoImpact, the same effects can be produced with the Tone Map Tool which also features in PhotoImpact 6 and 7. Tone Map is actually a more powerful and versatile tool, but Levels is simpler to use and has a more user friendly interface than Tone Map.

Levels was covered in Tutorial #1 but is also included here as a tonality and colour adjustment tool. The Levels tool enables amendments to three tonal parts of an image, namely highlights, midtones and shadows. When the Levels dialog box is open a histogram is shown which displays the distribution of tones in an image as a 256 step greyscale from pure black to pure white (see dialog box below).

The horizontal greyscale (Input Level) adjusts contrast by moving the black and white point sliders, while the grey point slider adjusts midtones. If the histogram display falls away before reaching the black and white point sliders, moving the sliders towards the edge of the histogram resets the image black and white points.

Moving the greypoint slider towards the white point slider darkens midtones, while moving it towards the black point slider lightens midtones.

If the Preview check box is clicked, adjustments are shown in the thumbnail image in the dialog box. Alternatively, you can preview the effect on the full size image by clicking the Preview button on the dialog box.


Because these simple adjustments often make significant improvements to a photos tonal range, checking and adjusting levels is often a good starting point with any image editing work.

Tone Map 1 (Preset Enhancements)

While Levels allows adjustment of three image areas, namely highlights, midtones and shadows, Tone Map allows up to 11 points for adjusting an images tonal range.

As with Levels, the histogram in the dialog box shows the distribution of tones in an image as a 256 point greyscale, with black on the left and white on the right of the horizontal scale. In addition, there is a line which can be moved and adjusted to alter the tonal range of the image. This line can be adjusted either using the preset enhancements from the pull down menu, or by adding customised control points to change the shape of the line, which then changes the images tonal range.

In the dialog box above, one of the preset adjustments (Darken Midtone) has been selected and applied to the Master channel. Similar adjustments can be made to the Red, Green and Blue (RGB) channels if required. The effects of any adjustments are shown in the righthand thumbnail.

Tone Map 2 (Custom Enhancements)

If Tone Maps preset enhancements do not give the type of results required, you can produce your own custom adjustments by adding Control Points and dragging the line to remap the tonal distribution. To add a Control Point, select Custom from the Enhancement pull down menu, then use the mouse to click one or more points on the line. When the points have been added, use the mouse to drag each point into its new position. The effects of these changes will show in the righthand thumbnail image.

Its also possible to add Control Points to Tone Maps preset enhancements for further adjustment and refinement. After selecting an option from the Enhancement pull down menu, click the Use Control Points box, then click points on the line that you wish to adjust, and drag these into their new positions.

Individual Control Points can be removed by selecting the point with the mouse, right clicking, and selecting delete. To remove all Control Points you have added, click the Reset button.

In the example left, two Control Points have been added to the line related to shadow areas and midtones. The shadow area Control Point (bottom left) has been dragged downwards slightly to darken shadow areas of the image. The midtone Control Point was not moved, but added to keep midtone areas unchanged. This has changed the line from being straight, into a slight S shaped curve, which for many reasonably exposed photographs will give a good tonal distribution from black to white (and other colours in between). Photographs with more under or over-exposure will probably require a larger degree of adjustment.

Brightness and Contrast

Brightness and Contrast controls are, as the name suggests, used for adjusting an images brightness and contrast levels. Adjustments can be made by moving sliders or clicking on thumbnails. Higher numbers on the slider controls produce higher levels of brightness and contrast. Use the Gamma slider for adjusting midtones.

Adjustments can be made to both the Master channel and Red, Green or Blue channels if required. When an adjustment is made with the slider controls, the effect of this adjustment is displayed in the middle thumbnails display (with a blue border around it). This setting can be saved if required to apply to other images. To save the setting, click on the Add button, give the selection a name and save in the Easy Palette for later use.

The Show Clipping display can be used to show on thumbnails which parts of the image will be converted to pure black or pure white as a result of selected brightness and contrast adjustments. This is useful for making sure shadow areas do not become too dark, or highlight areas become burnt out.

The Thumbnail variation slider controls the amount of variation, in terms of brightness and contrast, between the thumbnail images for selecting adjustment. Higher numbers increase contrast while lower numbers reduce contrast.

When the Brightness and Contrast dialog box is open, the default setting for thumbnails shows the whole image. This can be changed by clicking on the Thumbnail button (which opens the dialog box shown left) and selecting an alternative view, for example, zooming in to an area of specific interest. Click OK to return to the Brightness and Contrast dialog box, and the thumbnail view changes to the selected method.

Where are the selection tools located? The Standard, Lasso, Magic Wand and Bezier Curve tools are located on the Tool Panel towards the top left hand side (see area circled top left). The icons used for these tools are shown below.

Tip: If the required selection tool is not visible on the Tool Panel, put the mouse cursor over the selection tool icon, then left click and hold the mouse button down. This displays a 'flyout' menu (shown left), from which the appropriate tool can be selected. This can be used for any icon on the Tool Panel that has a small triangle in the lower right corner.

The Colour Range selection tool is located under Selections on the main Menu bar.

The Mask tool is located on the Tool Panel towards the lower left hand side (see circled area left), or alternatively, can be accessed from the Edit menu on the main Menu bar.

Standard Selection Tool
The Standard Selection tool is used to select regular geometric shapes, namely rectangle, square, ellipse and circle, which can then be editied as required. Generally speaking, standard selections have limited use for photo editing purposes, but they do have some uses.



In the example shown right, a rectangular selection was made on the image, then further edited to produce a vignette effect with soft focus graduated edges. This technique could be used on any type of photo, but is probably seen most often on portrait shots with a soft edged circle or ellipse shaped vignette.






Using the standard selection tool: On the Selection tool Attribute Bar (shown right), the required shape is selected first, then drawn on the image (or blank canvas) using a click and drag action with the computer mouse. Alternatively, a fixed size selection can be made by checking the Fixed Size box, then putting the required size (in pixels) in the dimension boxes alongside (width and height respectively).

Lasso Selection Tool: While the Standard selection tool is limited to predefined regular geometric shapes, the Lasso tool can be used for selections of any shape, and is especially useful for selecting irregularly shaped areas within an image, for example, a persons head in a portrait photograph, or a sky or foreground area in a landscape photograph. In the example below, the foreground rock and upper part of the water were selected with the Lasso tool, then further edited to make them darker, leaving the central image tones unaffected.

Using the Lasso tool
To make a selection using the Lasso tool, click the Lasso icon on the Tool Panel. In the Options menu on the Attribute toolbar (see below), select any of the three options you wish to use. For photo editing purposes, I would suggest all three options are selected. Checking the Editable Lasso option enables fine tuning of the initial selection (if necessary) before confirming its ok. This is useful for correcting any part of the initial selection you are not happy with. Once a selection is confirmed, you can no longer edit its shape, apart from deleting it and starting again. Checking the Preserve Base Image option is recommended to protect your original image from unwanted or accidental changes. The Anti-aliasing option is also recommended as this helps to smooth the appearance of curved selection lines so they appear less jagged.

When the relevant options have been selected, start the selection process by clicking a point on the edge of the area to be selected. Click carefully around the remaining edge areas to complete the selection, working back to the original start point. When back at the start, double click it to complete the initial selection. At this stage, you will have a selection line with a series of 'control points' indicating the selected area (see below, left).

The colours of the selection line and control points can be changed if required by clicking the Line and Node colour squares on the Attribute bar (see below), then selecting the desired colours from the Colour Picker dialog box that opens. This is helpful for making selection line and control point colours easily distinguishable from the image colours.

If the Editable Lasso option has been selected, the control points can be edited before finishing the final selection by dragging them with the mouse to a more accurate position. Additional control points can also be added to the selection by clicking on the selection line, then dragging and releasing the mouse at the appropriate point. A new control point will appear on the selection. When happy with the selection, click Finish on the Attribute toolbar. At this stage, the control points disappear and the selection is displayed as a dotted line (see above right). Once the selection is completed, filters or effects can be applied as required. Additional selections can also be made if further areas require editing.

Adding to, or subtracting from, a selection: There may be occasions when its necessary to edit a number of different parts of an image in the same way, for example, adjusting colour or contrast. You could select and edit each area separately, but its quicker and easier to make the selections and group them so you only need to carry out one editing procedure. If you need to do this, immediately after completing the first selection, check the plus (+) icon on the Attribute toolbar (see right) then continue to make the additional selection(s). When completed, any editing will be applied to all the selections grouped together. You can also subtract areas from a selection by checking minus (-) on the Attribute toolbar and selecting areas to be removed from the original selection. For example, you may start with a circular shaped selection, and need to remove a part contained within it.

Adjusting selection attributes: When a selection is completed, the basic shape cannot be adjusted, but it is possible to make some adjustments using options from the Selection menu on the Menu toolbar (see left). Useful options for photo editing are Invert, Expand/Shrink and Soften.

The Invert option could be used where the selection area is made within a central part of the image, and the intention is to edit the surrounding areas. For example, selecting the seagull in the photo above, then inverting the selection to edit the rock and water part of the image, rather than the seagull.

The Expand/Shrink option can be used to expand or shrink a selection between 1 and 64 pixels. This can be useful where a 'good fit' is required between adjacent edges of selected and non-selected areas, to avoid any 'gaps' between them. For photo editing purposes, its unlikely an expansion of more than one or two pixels would be required, but use the Preview option to check the effect of any changes.

The Soften option can be used to give a soft edge to a selection area, so it blends better with edges of the adjacent non-selected areas. However, this is best done by selecting the required soft edge size (in pixels) on the selection tool Attribute toolbar (see below) before making the initial selection with the Lasso tool. Soft edges up to 150 pixels can be made on the Attribute toolbar, compared to a maximum of 64 pixels on the Selection menu. The amount of soft edge required will vary depending on a number of factors, including file size and the effect you wish to achieve, so experiment with different settings. With practice, you will have a good idea of what values to use in different circumstances.

Using the bezier curve: Select the Bezier Curve icon from the Tool Panel menu (see above). Select the shape you wish to create from the Shape options on the Attribute toolbar (see right). For selecting irregular shapes, use the Free Path option.

Making a Bezier Curve selection has some similarity to the Lasso tool, in that selection points are created by clicking the mouse cursor on points along the edge of the shape to be selected, then double clicking when back at the start point. When a segment of the selection falls on a curved line, click, and then drag, the mouse pointer to create a set of control handle points (see below). These selection node control points can be used to facilitate drawing curved lines more smoothly than the Lasso tool.
Using the Bezier Curve to its full potential does require practice, but is a useful skill to develop.

Editing a bezier curve:
When completed, the selection can be edited at any time by right clicking the mouse, and selecting Edit Path from the available options. The existing control points can be moved as necessary to fine tune the selection by clicking on a point, and dragging it with the mouse cursor to its new position. Additional control points can be added to a selection, and exisiting ones deleted as well.
Tip: If you wish to make a selection that contains only curved lines, PhotoImpact also has a Spline tool which is ideal for this purpose. The Spline tool can be found within the Path drawing tools.



Magic Wand Selection Tool:
While tools such as the Lasso and Bezier Curve are used to make selections on the basis of shape, the Magic Wand tool is used to make selections on the basis of colour. For photo editing, the Magic Wand generally works best when selecting either a distinct colour, or a limited range of colours, particularly where colours are confined to a limited area of the image.

Example: A good example of using the magic wand tool would be selecting a clear blue sky in a photograph. The sky in the original photo (far left) is a relatively uniform colour, and similar tones mostly occur in one area of the image. There is also a clear colour difference between the sky and adjacent edge areas, in this case the grey coloured griffin, which also facilitates selection with the magic wand. After selecting the sky with the magic wand, additional editing tools were used to darken the sky, producing a deep blue colour similar to that obtained from a polarising filter on a camera lens (see above right).

To make a selection using the Magic Wand, click the magic wand icon on the Tool Panel. Continue by checking the required selection method (line or area) on the Attribute toolbar, and the estimated level of similarity required for a good selection. In this example, selection was made by line, with similarity value set initially to 1. The 'Search Connected Pixels' check box was also chosen to confine selection to the sky area. When the selection criteria are completed, drag the mouse cursor across the colours that need to be selected.

Setting similarity value: Setting the similarity value is generally trial and error, and you may wish to try starting with a low number such as zero or 1. A value of 0 selects neighbouring pixels with exactly the same colour value, while a value of 255 selects pixels of all colours (in other words, the entire image). For photo editing, values between 0 and 25 will probably be the most commonly used settings.

Examples shown below indicate the extent of the magic wand selection using similarity values of 1 (left) and 25 (right). A similarity value of 1 only selected part of the sky, indicating a greater degree of similarity is required to select all the sky. The similarity value was increased using trial and error until all the sky was selected. In this example, a value of 25 produced a good selection.

Adding to a selection: There may be occasions when its necessary to expand the current selection, to include further areas not currently selected. In the example photograph, there are areas of unselected sky due to the 'select connected pixels' option being used (see left). This is not a problem as further colours can be added, or subtracted, to the current selection.

To add, or subtract, from the initial selection, click the plus (+) or minus (-) icon on the Attribute toolbar (see right), then continue making further selections with the magic wand as previously, until the selection is satisfactory.



Colour Range Selection Tool:
Like the magic wand tool, colour range is also useful for making selections on the basis of colour. While the magic wand selects all pixels within a specified colour range, the colour range tool creates a gradient selection mask based on each pixels colour similarity to the specified colours. This makes it an excellent tool for selecting non-adjacent similar colours across an image, particularly where a soft edge is preferable on non-selected adjacent areas.

In the example shown right, the yellow flowers in the foreground container look a little muddy and have an orange cast (original photo). Trying to select each yellow flower head with something like the lasso tool would be very difficult and time consuming. Using the magic wand would be more successful, as this makes selections on the basis of colour, but produces relatively hard edges between selected and non-selected adjacent areas. The image on the far right shows the edited flowers after making a selection using colour range. The yellow colour in both the foreground and background flowers is brighter and more accurate, compared to the original image.

A further comparison between magic wand and colour range is shown left using a magnified section from the example image. The yellow flowers on the right image were selected using colour range, and those on the left using magic wand. Brightness value was increased by 50 in both cases after the selection was completed. The magic wand version shows a hard edge between selected and non selected areas, while the colour range selection has a much smoother transition. Although its possible to soften edges of the magic wand selection (within the Object Properties dialog box), diminishing the difference between the two methods, the colour range version produces a more subtle and better result, with better gradation across selected areas. However, its always worth trying alternative methods to see which work best.


Using colour range selection: Click Selection on the Main menu bar, then select Colour Range. The dialog box shown right will appear. Selections can be made using either Sampled Colours or the Standard option. The former is based on a selected colour, while the latter is based on highlight, midtone and shadow areas within the entire image. In this example, the Sampled Colours option was selected (see right) then the eyedropper tool used to select the required colour in the left hand pane.

Move the Similarity slider to increase or decrease the level of similarity to the colour selected with the eyedropper. Changes are shown in the right hand panel as a black and white greyscale image (providing the Preview option is checked). You can also use the add (+) and subtract (-) eyedroppers to increase or decrease a selection range.

If the paintbrush tool is used to create a mask, you may find it easier to have the Brush Panel open (see left) so changes in size, shape or transparency, for example, can be done more easily.

As you work on creating a mask, its often useful to toggle the Quick Mask icon (on the Tool Panel) on and off to check progress. When quick mask is switched off, the selection will show as a dotted line on the image (see right). Continue editing the mask until its considered ok. Switch the Mask Mode off to convert it into a selection. The selection is now complete and editing tasks can be applied as required.

Saving Selections (Temporary): To save a selection temporarily while working on a file, select 'Store Selection' from the Selection menu. This places a copy on the Selection Manager. To display the stored selection, click the 'Selection Manager' icon on the Panel Manager. Stored selections can be retreived and modifed if necessary, using selection tools described earlier in this tutorial.

A Note on Selections and Objects in PhotoImpact

Selections: These are parts of an image created by PhotoImpact selection tools (for example, Lasso Tool) and are bordered by coloured dotted lines (known as the Selection Marquee). Selections can be expanded to include multiple parts of an image. When you edit a selection, you are editing the base image.
Objects: These are selected parts of an image initially created by PhotoImpact selection tools, then converted to an Object that 'floats' above, and is independent of, the base image. When selected with the Pick Tool they have an animated black and white dotted line (often referred to as 'marching ants'). Because Objects are independent of the base image, you can move and manipulate them without effecting other objects or the base image. They also offer the opportunity for more advanced editing tasks such as adjusting transparency or using different modes to blend parts of an image together (for example, hue and saturation, luminosity etc).

Step 1: Draw Boundary

First, open the image in PhotoImpact, then select the Extract Objects option (Menu Bar-Object-Extract Object). The dialog box shown right appears. The cursor changes to a brush shape, which is then used to draw an enclosed boundary around the object. Before doing this, you may need to change the colour and thickness settings of the brush. The default brush colour is red, but as the object being selected is also red, I double clicked the Color box and selected a blue colour from the 'Colour Picker' box. This gives a better contrast between the red flower and the boundary line drawn around it.

The appropriate brush size will be dependent on the file size being edited. For relatively large files, for example, 3000 by 2000 pixels, a setting of about 70 to 80 will probably be sufficient. For smaller file sizes, such as those used on a webpage, a setting of about 10 to 15 will probably be sufficient.

If you make a mistake while drawing the boundary line, either click the 'Clear' button to start again, or alternatively, click the Eraser button and delete the areas you wish to correct. When the boundary line has been drawn, click Next (or Extract Object).

Step 2: Set Extraction Detail Level

After drawing the boundary line, move the Extraction Detail slider to the required setting (between Low and High). You will probably get a better selection using the High setting, but this is trial and error to some extent.

Incidentally, when drawing the boundary line in Step 1, it is possible to make more than one selection area if required. Click the cursor outside of the object being selected (in this case, outside the flower boundary line). This removes the unselected area, which will now show as a transparent background. If you inadvertantly clicked in the wrong area and the object you wanted to select has disappeared, simply click the Invert button in the dialog box, and the correct selection will show.

Step 3: Make The Extraction

Click the Extract button, and after a few seconds, the boundary line will disappear leaving the current selection displayed. If the selection looks alright, click the OK button to finish the extraction process.

Until the OK button is clicked, the current selection can be edited where necessary. If the object being selected from the image was clearly defined and well separated from the backgound, you will probably have a good selection first time round. If the degree of separation between the object and background was less well defined, its likely that some refinement of the selection will be required.

Step 4: Refining A Selection

If your selection at stage 3 is unsatisfactory, click the Refine Object button, and you will be able to amend the selection. In the example shown right, there is still some detail showing from the background which needs to be removed.

First, set the background colour, if necessary, so there is a good contrast between the selection (double click the Background colour box, and select a suitable colour). The transparency of the background colour can also be adjusted if this helps, by entering a number between 0 and 100. In the example shown right, the background colour has been set to black, and transparency to zero.

To edit the selection, toggle between the brush and eraser tools (highlighted red, above) to paint in, or remove, details as required. There are three settings to consider: the size of the brush (or eraser), along with the transparency and softness of the brush/eraser being applied. All of these will vary depending on things like file size, degree of accuracy required, and level of separation between the selected object and image background. A 'trial and error' approach is probably the best way for learning what settings suit which circumstances.

The Finished Selection

After clicking OK to complete the process, the Extract Object dialog box will close and the new selection object appears as a layer above the base image, identified by a dotted line (see right). At this stage you are now able to edit the object using any of PhotoImpacts editing tools. In this example, the flower was copied and pasted into another image (see below, left).

Saving The Selected Object

If you are likely to need the object again in the future, either for further editing or for use in another image, you can save a copy to the EasyPalette. Ensure that the object is 'selected', then select Object>Copy to Object Library, from the Main Menu bar, and add the required details (see right). Click OK to complete.

Hue and Saturation: Controls in the Hue and Saturation dialog box (shown left) can be used as follows :

Hue: shifts the hue (colour) value of each pixel in an image by the amount specified. For example, a yellow pixel will become blue if you set the hue value to 180.

Saturation: increases or decreases the strength of colour in an image. Fully reducing saturation results in a grayscale image, while fully increasing makes colours very rich.

Lightness: adds levels of white or black over the image depending on the value selected. Fully reducing lightness makes an image completely black, while fully increasing lightness makes it completely white.

Method: These options determine how colours in an image are manipulated.

Master: The upper coloured bar represents the original hues of an image, while the bottom bar indicates hues that will replace them. For example, if the red colour in the upper bar is in line with blue in the bottom bar, red colour in an image will be replaced with the indicated blue color.

Range: This uses 4 slider controls between the 2 coloured bars to limit any adjustments to specific colour ranges within an image. The central dark gray segment is the area that adjustments will mainly effect, while the 2 light gray outer segments indicate colour tones that will be lesser effected. You can move the 4 slider controls as a group into the required color range by moving the dark gray area, then seperating the sliders accordingly (see Dialog box above). Restricting colour adjustments to a limited range is useful for landscape photos when you wish to increase, for example, the lightness/darkness and colour saturation of skies. In the example above left, the range method has been used to restrict colour adjustments to blue tones on the image, leaving other colours unaffected.

Colorize: This method is useful for adding tones of a specific colour to an image. In the dialog box shown above, the Colorize method has been used to change the original colours into a sepia toned image. The bottom coloured bar changes as the hue slider is moved, showing the colour represented by the number next to the hue slider control. Once the hue has been selected, further adjustments can be made using the Saturation and Lightness sliders where required.

If the Preview box is checked, any adjustments will be shown in the right hand thumbnail image.

Colour Replacement: The Colour Replacement option is similar to the Range method available in Hue and Saturation, but gives more precise control over colour selection and adjustment. The eyedropper is used to select a colour in the left hand thumbnail, then the Similarity slider adjusted to select the range of colours (related to the eyedropper selection) to be effected.

In the example shown left, a point on the grey cloud was selected with the eyedropper, then Saturation increased and Lightness decreased to make the clouds more prominent. The eyedroppers with plus and minus signs can be used to add or subtract a colour from a selection.

Mask View can be used in conjunction with the Similarity slider to give a visual indication of how changes to hue and saturation will effect the image. Black areas in Mask view will not be effected by adjustments, while white areas will be fully effected. Midtone areas will be partially effected by selected hue and saturation settings.

Colour Balance - Setting a Black Point
Some photographs often look a little muddy and flat because parts of the image that should be black appear as dark brown. Setting the black point on an image can be done easily and quickly with Colour Balance.

When the dialog box is opened, click on the Smart tab then use the zoom and pan tools to move to an area of the image that should be black, such as shadow areas. Use the eyedropper tool and select the colour you wish to replace. The selected colour then shows in the Current colour box. In the example shown left, the shadow from the Millenium Eye on the building roof was selected as the colour to adjust.

To replace the selected colour, click on the Desired colour box, and the Ulead Colour Picker appears (see right). Select the desired colour from the options available, click ok, then check the effect in the Preview window. If the result is too dark or light, repeat the process using a different black point until the desired effect is obtained.





















Colour Balance - Overall Adjustment
In addition to setting black (or white) points on an image, Colour Balance can also be used for adjustments across the whole range of image colours using Preset options in the dialog box. The current image colours are displayed in the centre cell, with variations shown around it, for example, warmer or cooler toned versions of the original. Clicking on one or more of the thumbnails will apply the selected colours to the image.

Tone Balance specifies the type of color adjustment applied to an image. Highlight adjusts light areas, Shadow modifies dark areas, while Midtone adjusts intermediate tones. When the Auto option is selected, adjustments are applied to all tones on the image.

When Show clipping is checked, the thumbnails show image parts that are converted to pure black or pure white due to adjustments in brightness and contrast.

To start, copy the original image (Edit>Copy), then use Paste As Object to place another copy above the original (Edit>Paste>As Object).

With the new layer object selected, open the Flatten Uneven Area dialog box (Effect>Blur>Flatten Uneven Area). This opens the dialog box shown left. The left thumbnail shows your start image, while the right thumbnail shows the applied effect with the selected settings. In this example, settings were 8 (Low Pass), 8 (High Pass) and 3 (Filter). Increasing the numbers increases the strength of the effect. Try experimenting with different settings until you obtain the effect that best meets your requirements.

Because the filter effect was applied to the whole layer object, some areas where the effect is not wanted, for example, the eyes and mouth, need to be removed to allow the unaffected underlying base image to show through. This can be done using the Object Paint Eraser Tool.

To change a file from RGB to Greyscale, select Format from the Main toolbar, then Data Type and Greyscale (8 bit). Alternatively, click the RGB icon in the bottom right hand corner of the application screen (shown right), and select Greyscale.

Ensure the Create New Image option is checked (see right) so your original image remains safe. This will create a new black and white version of your colour photograph which can be saved separately from the original.

This method is quick, and often produces acceptable results, but the user has no control over the end result as its produced automatically by the software. An example of how colours look after conversion to Greyscale is shown below.
The image shown left was produced by converting a RGB file to Greyscale. Blue in the original image has changed to a dark tone in the Greyscale version, with red showing as a midtone, and green and yellow becoming progressively lighter. Colours in the original that have the same brightness and saturation show as different tones in the Greyscale version, so red, yellow and blue are still clearly distinguished from each other.

Instead of changing the file type to Greyscale, its possible to retain the RGB format, and remove colour by using the Hue and Saturation tool. To open the Hue and Saturation dialog box, click Format on the main menu, then select Hue and Saturation (see left). If you want to retain the colour version of an image, select Duplicate from the Edit menu, then work on that instead of the original.

The Calculation Tool can be opened by selecting Calculation from the Format menu. The dialog box shown below then appears. Select a channel from the Foreground pull down menu, then click OK. This opens a new file - still in RGB format - which can be saved or edited further as required.

A single channel file may be all thats necessary in terms of converting a colour photograph into black and white, but if these alone do not produce the desired result, then further options are available by combining channels, and using blending modes.

The final image of the King Vulture was produced using the Red and Green channels, with a Green Mask, and the blending mode set to Inverse of Multiply.

To complete my black and white image, I made the background a little darker. To do this, I copied the Calculation Tool output image, and pasted it as a new layer object. I changed the blending mode of the new layer from Normal to Multiply, then reduced opactity to 50%. Finally, the Object Paint Eraser Tool was used to delete the area covering the bird on the layer copy, revealing the base image underneath.

Avoiding Confusion
Before progressing further, it should be noted that references to file size in this tutorial concerns the physical dimensions (height and width, in pixels) of an image, and not its memory size (megabytes or kilobytes). This is an area that often causes confusion for newcomers to digital photography.

Effect of Resampling on Image Quality
Although resampling can be used to increase or decrease an images dimensions, there is always some loss of quality involved in the process, and quality probably suffers more when increasing file sizes, particularly where increases are large (eg, more than 100%). If your main requirement is to increase file size by large amounts, it may be worth investing in specialist software such as Genuine Fractals, otherwise, PhotoImpact or similar image editors should generally be sufficient for resampling work. Providing that the original image is generally good quality (ie reasonably sharp), and the change in file dimensions following resampling are not excessive, then the quality of the final file (or print) should be good.
The following parts of this tutorial show how to resize images using PhotoImpacts Resize dialog box.

Step 1: Open the Resize Dialog Box To open the Resize dialog box, click Adjust on the Main menu bar, and select Resize. The dialog box shown right will appear. There are a number of settings to consider and these are discussed in the sections below.

The Active Image section shows the current image size, in pixels, and the current resolution, expressed as the number of pixels per inch (ppi). Digital cameras often produce jpeg files with a resolution of 72 ppi, so its not uncommon to find this is the default resolution of an image when opened in image editing software such as PhotoImpact.
If the resized image will only be displayed on a computer monitor, there is no need to change the resolution as 72ppi is fine for this purpose. If the resized image is for producing a printed version of the file, then a higher resolution such as 300 ppi would produce a better result. More information is given on this in the 'Resolution' section below.

Step 2: Identify what needs to be resized This section is used to identify which part(s) of the current image will be resized. Often, it will be the 'base' image, or a copy of it, but for images that have been edited and contain 'objects' - known as 'layers' in most other image editors, there is also the option to resize either a selected object (layer), or the base image and any objects it contains as well. Unless your image contains any objects, the Base image will be the appropriate setting for resizing an image.

Step 3: Identify the required output sizeThe next step is to identify the required output size of the image. These can either be Standard (default) or User Defined image sizes. Before selecting a size though, ensure the 'Keep Aspect Ratio' box is checked (highlighted red, right). This keeps the height and width ratio of resized images the same as the original source file, otherwise you may end up with a distorted image.

Select the preferred measurement unit from the picklist (highlighted blue, right). In this example, 'Pixels' have been selected. Click the 'User Defined' checkbox and enter the required size for the output file. If the 'Keep Aspect Ratio' box is checked, you only need to enter either the Width or Height as the second size will be calculated automatically from the first entry.

You may wish to explore some of the Standard sizes available on the picklist, but ensure that the height/width proportions of these are identical to the height/width proprtions of your image otherwise the resampled output file may be distorted. If in doubt, always select the User Defined option, and ensure the Keep Aspect Ratio box is checked.

Adding User Defined Sizes
Its possible to add your own customised sizes to the User Defined options. This is useful if your original source and resampled output files are aways the same height/width proportions.

To add a customised size, click the red tick icon (highlighted red, left), type in a relevant name and click OK. The name you add will be displayed on the menu for the user defined size options. To access the size you defined, click the red tick icon which will display your custom file size on the pick list options (see below).

Step 4: Set the Resolution If the resized file is intened for use on a webpage, or for emailing to a friend, leave the resolution at 72ppi as this is the default setting for webpage images.

If the resized file is to be used for printing, then a higher resolution is required. For best quality printing, set file resolution to around 200 to 300 ppi. Its said that the human eye is unable to resolve resolutions of more than 300 ppi, so anything higher than this produces unnecessarily large file sizes.

Approximate output print sizes for combinations of image size and file resolution are shown in the table below. To calculate the print size for other combinations , simply divide the image dimensions (pixels) by the file resolution (pixels). This will give the output print size in inches.

Controlling Print Size by Changing File Resolution The table shown above illustrates that print size can be controlled, to a certain extent, purely by changing the file resolution. In other words, its not always necessary to resample a file to produce a certain output size. For example, if you have an image file with dimensions of 2000x1500 pixels, and want to produce a print of approximately 5x4 inches, setting the file resolution to 400ppi will produce the required print size (ie 2000/400=5) without resampling the file. This is a better option than resampling as the original file dimensions are left unchanged, which means there is no loss in image quality. By contrast, resampling a file always involves some loss of image quality.

This method does not work well if the file resolution required to produce the print size is lower than, for example, 100ppi. Using a low file resolution will probably produce a print with pixels that are too prominent to produce continuous tone as normally seen in a photo. The image shown right illustrates what a print with a low file resolution would probably look like.

Step 5: Select the Resample Method PhotoImpact has three ways of resampling images, namely Bicubic, Bilinear and Nearest Neighbour. These are essentially mathematical equations, known as interpolation algorithmns, which add new pixels based on the existing pixels in an image. Fortunately, its not necessary to understand how they work, but it is useful to know about the characteristics of their output to decide which method to use. The Bicubic method produces a soft image (which can be sharpened) with the smallest file size, while Nearest Neighbour produces a sharp image with a larger file size. Bilinear resampling produces an image approximately midway between the other two methods in terms of sharpness, but with a relatively large file size (ie, in terms of megabytes or kilobytes).

Select the preferred resampling method from the picklist and click OK. The file will then be resampled (resized) according to the options selected in the Resize dialog box.

When editing images you may wish to consider using a duplicate copy rather than an original, to ensure your original file is unaffected if any problems occur during the editing process. This is good practice, and a habit worth developing.

Comparison of Resampled Output Files A comparison of files produced using PhotoImpacts resampling methods are shown below. Because the images were saved as jpeg files to display on this webpage, quality has suffered a little due to file compression artefacts, but even allowing for this, subtle differences can be seen between the different methods. The methods shown are bicubic (top left), bilinear (top right) and nearest neigbour (bottom left).

The preferred method for image resampling will of course vary with personal preferences and quality of the original images. In general, I use Bicubic resampling most of the time, and although this produces a softer image than other methods, tonal quality is generally better and sharpness can be increased with use of the Unsharp Mask tool. Bicubic resampling also has the advantage of producing smaller file sizes (ie megabytes) than the other two methods. The final image (below) was resized using bicubic resampling, then sharpened with PhotoImpact's Unsharp Mask tool.

Before You Start
Before using Batch Manager, you should consider the number and size of files you want to edit, and whether your computer has sufficient memory or processing power to do all the tasks you want to carry out. If your photos are relatively small (eg 2MB jpeg files) you could probably open quite a few files and have no problems. However, if each file was a 15MB tiff file, trying to open 20 of these at the same time and then running all the editing tasks may give your computer problems. You may want to experiment and see what works best for you and your computer. If in doubt, start with a small number of photos, then do more if your computer copes ok with the demands placed on it.

Getting Started
To begin the process, open the files in PhotoImpact that you want to edit, then click Window on the standard toolbar and select Batch Manager (see screenshot right).

When the Batch Manager dialog box opens, a thumbail and file name is shown for each image currently open in PhotoImpact (see below, right).

Batch Manager Settings Select the images you want to work on, either by clicking the Select All button, or clicking individual thumbnail images (and holding [Ctrl] or [Shift] keys) to make multiple selections. Having done that, first select from the dropdown list which Category you wish to use, then select the operation you want applied to the selected thumbnails. In this example, the photos are being resized, so the Category setting is Adjust and the operation Resize.

As can be seen from the screen grab, options that appear in the Category menu are those available on the Standard Toolbar. This means you need some awareness of where appropriate options are normally found in PhotoImpact. If you are unsure, look at the options available in each menu before starting the Batch Manager process.

Completing Tasks
When all the selections have been made, clicking OK opens the dialog box of the selected operation, in this example, the Resize dialog box. Adjust the settings as required then click OK to perform the selected task on each of the photos.

If there are additional tasks you need to complete, simply select Batch Manager again from the Standard Menu toolbar and repeat the actions as above until all tasks are completed.

If you don't like the output from the Batch Manager operation, you can always right click the mouse and select Undo to go back to the previous image state.