Other Tonal Control Effects

The Tonal Control commands in the Effects menu let you adjust or alter colors in an image.

Adjust Colors

The Adjust Colors effect lets you control the hue, saturation, and value of an image in much the same way as you would adjust your television.

Use the Adjust Color dialog to change the hue, saturation, and value of an image.

To adjust colors

1. Select a layer or area of the canvas.

If you want to adjust colors in the entire image, select nothing.

2. Choose Effects menu > Tonal Control > Adjust Colors.
3. In the Adjust Color dialog box, choose one of the following methods from the Using pop-up menu:

• Uniform Color adjusts all pixels equally.
• Paper uses the selected paper grain to control the color adjustment.
• Image Luminance uses the luminance of the image as the model for color adjustment. Areas of greater luminance are adjusted more.
• Original Luminance uses the luminance of the clone source as the model for color adjustment. If you have not set up a clone source, the current pattern is used.
• [Alpha channel] or [Layer mask] uses the selected alpha channel or layer mask as the model for controlling color adjustment. For example, a black-to-white gradation in the channel or mask will allow you to adjust the color progressively across the image. Where the channel or mask is black, colors are not changed. Where the channel or mask is white, the adjustment applies fully. Transitional areas receive proportional color adjustments.

4. Adjust the sliders to control the overall hue, saturation, and value levels in the selection.

• Hue Shift adjusts the colors of the pixels by changing their hue. Moving the slider to the right shifts the hue counter-clockwise on the color ring.
• Saturation adjusts the amount of pure hue in the color. Moving the slider all the way to the left creates a grayscale image.
• Value adjusts color brightness. Moving the slider to the left darkens colors.

You can see changes in the Preview window. You can drag in the Preview window to see different areas of the image.

If you want to return the image or selection to the way it was, click Reset. This resets all of the sliders.

5. When you are satisfied with the settings, click OK to apply the effect.

• With all methods other than Uniform Color, pixels assigned higher luminance receive a greater color adjustment.

Adjust Selected Colors

Adjust Selected Colors is similar to the Adjust Colors effect, but it works only on a specified range of colors within an image. You choose a color in an image and adjust colors within a range of that color. You could, for example, turn yellow peppers to red peppers.

You can adjust colors that are exactly the same as the color you select, or you can choose colors within a range, based on proximity (on the color wheel or color space) to the selected color.

Selective color adjustments change only certain colors in the image.

The Extents sliders determine the extent of the HSV color space around the selected center color:

• H Extents controls the number of hues adjusted. Only hues within the specified percentage of hues on the color wheel are adjusted.
• S Extents controls the range of saturation adjusted. Only saturations within this range are adjusted.
• V Extents controls the range of values adjusted.

By combining these three settings, you can set up a very specific range of colors to adjust. For example, you can limit changes to a very specific shade of red.

Feather affects the softness at the edge of the selected colors. These sliders can help you create smoother transitions between the replaced color and the original.

A replaced color with and without feathering.

The choice of methods is the same as for Adjust Colors. For more information, refer to "To adjust colors:".

To adjust a selected color

1. Choose Effects menu > Tonal Control > Adjust Selected Colors.

The Adjust Selected Colors dialog appears.

2. Move your cursor over the original image in the image window (your cursor becomes a dropper), and click the color you want to adjust.

The Colors palette displays the selected color as the primary color.

3. Choose a method from the Using pop-up menu to determine what Corel Painter will use as the source for the color adjustment.
4. Adjust the Extents and Feather sliders to select a range of colors to adjust.

Move the Extents sliders to the right to increase the amount of color space affected by the effect.

5. Adjust the bottom three sliders to control the overall hue, saturation, and value levels.

You can see changes in the Preview window. You can drag in the Preview window to see different areas of the image.

If you want to reset the sliders to the default settings, click Reset.

6. When you are satisfied with the settings, click OK to apply the effect.

Brightness/Contrast

The Brightness/Contrast dialog adjusts the brightness and contrast of the overall image in RGB.

Before and after Brightness/Contrast.

You can also adjust brightness and contrast as a function of dye densities by adjusting the dye concentration. Refer to "Dye Concentration" for more information.

To adjust RGB brightness and contrast

1. Select a layer or area of the canvas.

If you want to apply the effect to the entire image, make sure there are no selections.

2. Choose Effects menu > Tonal Control > Brightness/Contrast.

The Brightness/Contrast dialog appears.

3. Drag the upper slider to adjust image contrast. Drag the lower slider to adjust image brightness.

The image is adjusted when you release the mouse or stylus.

If you want to reset the sliders to the default settings, click Reset.

4. Click Apply.

Equalize

The Equalize effect improves contrast, adjusting black and white points and distributing the brightness levels throughout the entire range of available levels.

Before and after Equalize.

Corel Painter lets you equalize an image by creating a histogram showing the number of pixels for each brightness level value and then allowing you to adjust those values.

Equalize also allows gamma adjustment, which lightens or darkens an image without changing highlights or shadows.

To equalize colors

1. Select a layer or area of the canvas.

If you want to apply the effect to the entire image, make sure there are no selections.

2. Choose Effects menu > Tonal Control > Equalize.

Corel Painter automatically adjusts the image or selection so that the lightest color is white and the darkest color is black.

3. In the Equalize dialog box, adjust contrast by dragging the black and white markers under the histogram.

Any values in the image located to the right of the white marker become white; any values to the left of the black marker become black.

4. Adjust the gamma by doing one of the following:

• Move the Brightness slider to the right to increase gamma, making the image darker.
• Move the Brightness slider to the left to decrease gamma, making the image lighter.

Changing the gamma adjusts only the midtones of an image and leaves the black and white areas untouched.

5. Click OK to apply changes.

A preview of the changes is applied to the original image, but is not final until you click OK. If you want to revert to the original image, click Cancel.

• If you made a selection and you want to equalize the entire image, enable Apply to Entire Image in the Equalize dialog box.

Negative

The Negative effect inverts all the colors in your image or in the selected layer.

Positive and negative versions of an image.

To invert colors

1. Select a layer or area of the canvas.

If you want to invert the entire image, select nothing.

2. Choose Effects menu > Tonal Control > Negative.

Posterize

Posterizing reduces the number of color levels an image contains.

To posterize an image

1. Select a layer or area of the canvas.

If you want to apply the effect to the entire image, make sure there are no selections.

2. Select Effects menu > Tonal Control > Posterize.
3. In the Posterize dialog box, specify a number of levels.

The fewer levels, the more dramatic the effect.

4. When you are satisfied with the settings, click OK to apply the effect.

• To posterize an image combined with a paper grain, refer to "Apply Screen".
• To posterize to two levels and also adjust the brightness, refer to "Equalize".

Video Legal Colors

The Video Legal Colors effect makes the colors in an image compatible with video. Colors that aren't possible in video are converted to video legal colors.

Only bright yellows and cyans are not video legal. Corel Painter supports both the National Television Standards Committee (NTSC) for the U.S. and Phase Alternation by Line (PAL) for European video systems.

To apply video legal colors

1. Select a layer or area of the canvas.

If you want to apply the effect to the entire image, select nothing.

2. Choose Effects menu > Tonal Control > Video Legal Colors.
3. In the Video Legal Colors dialog box, choose NTSC or PAL from the System pop-up menu.

Posterize Using Color Set

Corel Painter can posterize your image based on a color set. This allows you to create an image with only a specified set of colors in it. This is useful for multimedia work, as well as applications like silkscreening.

This effect can also be used to reduce colors in an image so that it appears correctly on the Web. For more information, refer to "Working with Posterize Using Color Set".

To posterize an image using a color set

1. Select a layer or area of the canvas.

If you want to apply the effect to the entire image, select nothing.

2. Open or create a color set.

For instructions on creating a color set, refer to "Using Color Sets".

3. Choose Effects menu > Tonal Control > Posterize Using Color Set.

The image is reduced to the colors in the current color set.