Converting color images to black and white
Everyone loves the elegant and artistic look of black-and-white photos, but most people cannot capture them with their digital cameras. Fortunately, Corel PHOTO-PAINT® includes several tools that let you quickly and easily convert your color photos to black and white.
Converting an image to grayscale
Extracting the Luminance channel from an image in the LAB color mode
Desaturating the colors in an image
Converting an image to monotone
Using the Image Adjustment Lab
Conclusion
Converting an image to grayscale
The quickest way to remove the color from a photo is to convert it to grayscale. The grayscale color mode defines color by using only one component – lightness – which is measured in values ranging from 0 to 255. When you convert a color photo in the RGB color mode to grayscale, the colors are replaced with varying shades of gray. So, essentially, when you convert a color image to grayscale, you emulate the look of a black-and-white photo.
First, make sure that your image is in the RGB color mode by clicking Image > Convert to RGB Color (24-bit). Then, choose Image > Convert to grayscale (8-bit).
Extracting the Luminance channel from an image in the LAB color mode
Extracting the Lightness channel from an image in the LAB color mode is another quick way to create the black-and-white effect. The LAB color mode consists of the Luminance (L), red to green (A), and blue to yellow (B) color channels. Since the color channels in a LAB image are stored separately, you can extract the Luminance channel and save it as a grayscale image.
First, convert your image to the LAB color mode by clicking Image > Convert to > Lab color. Then, split the channels by clicking Image > Split Channels to > Lab.
Display the Luminance channel by clicking Window, and choosing the file name that begins with "L-".
Desaturating the colors in an image
Another simple way to convert an image to black and white is to desaturate its colors. In this example, you will apply the Desaturate filter to a lens on top of the image. The Desaturate filter creates a grayscale image without changing the color mode by automatically reducing the saturation of each color to zero, removing the hue component, and converting it to its grayscale equivalent.
By applying the filter to a lens, you can view the effect before you apply it to your image. The lens is created as a separate object on a layer above the image. With the image open, click Object > Create > New lens. Choose the Desaturate filter from the Lens name box, and then click OK.
If you like the effect, you can combine the lens with the image background by saving it. If you don't like it and want to try another technique, select the lens, and press Delete.
Which technique is best?
These three techniques offer quick ways to produce a black-and-white image from a color photo. In most cases, the differences in the converted images will be subtle – a desaturated image may contain less detail or be slightly darker than the same image in grayscale, while the image produced from LAB might appear more crisp.
From left to right: the original color image; the image converted to grayscale; the Luminance channel extracted from the image in LAB color mode; and the image with the Desaturation filter applied to a lens.
The tonal range of the color image can also affect its appearance when you convert it to black and white.
From left to right: the original color image; the image converted to grayscale; the Luminance channel extracted from the image in LAB color mode; and the image with the Desaturation filter applied to a lens.
Then again, the differences may be apparent only when you print the images.
Converting an image to monotone
A monotone image is a grayscale image that is colored with a single ink. In this example, you will convert the image to monotone and use shades of black to achieve a black-and-white effect. You will also learn how to adjust the shading and intensity of the image.
With the image open, click Image > Convert to > Duotone. Choose Monotone from the Type list box.
On the left, the original color image; on the right, the monotone image.
Adjusting the tone curves
When you convert an image to monotone, a tone curve grid that represents the dynamic ink curves that are used throughout the conversion is displayed. The horizontal plane (x-axis) displays the 256 possible shades of gray in a grayscale image (0 is black; 255 is white). The vertical plane (y-axis) indicates the intensity of the color black (from 0 to 100 percent) that is applied to the corresponding grayscale values.
To adjust the tone curves, click the ink tone curve on the grid to create a node, and then drag the node to adjust the amount of color at that point on the grid.
The tone curve grid.
Click the Split pane button 
. In the right-hand pane, drag the image to see the changes as you apply them.
Using the Image Adjustment Lab
By uniting the most important manual and automatic controls required for common color and tone corrections, the Image Adjustment Lab offers a fast, intuitive way to achieve professional results with your images. In this example, you will use the Image Adjustment Lab to remove the Saturation element from your photo. Next, you will adjust the color and tone of the image to achieve the best possible effect.
With the image open, click Adjust > Image Adjustment Lab. To view the changes as you work, click the Create Snapshot button 
, and then click the Before and after full preview button. Next, remove the color saturation from the image by dragging the Saturation slider to the its left-most position.
The Image Adjustment Lab window should look like this:
By starting at the top-right corner and working your way down, you can select only the controls you need to correct the problem areas in your image.
The Hints panel provides information about each control. When you click a control, a hint is displayed, telling you how to use the selected tool.
The Hints panel.
Using automatic correction controls
You can begin by using the following automatic correction controls:
The automatic correction controls.
- Auto adjust
— automatically corrects the contrast and color in the image by detecting the lightest and darkest areas and adjusting the tonal range for each color channel. In some cases, this control may be all you need to improve an image. In other cases, you can undo the changes and proceed with more precise controls. - Select white point tool
— automatically adjusts the contrast in the image according to the white point that you set; for example, you can brighten an image that is too dark by using the Select white point tool. - Select black point tool
— automatically adjusts the contrast in an image according to the black point that you set; for example, you can darken an image that is too light by using the Select black point tool.
Adjusting brightness and contrast across the entire image
You can brighten, darken, or improve the contrast in an image by using the following controls:
The Brightness and Contrast controls.
- Brightness slider — lets you brighten or darken the entire image. This control can correct exposure problems caused by too much light (overexposure) or too little light (underexposure) at the time the photo was taken.
- Contrast slider — increases or decreases the difference in tone between the dark and light areas of the image. Moving the slider to the right makes the light areas lighter and the dark areas darker.
Adjusting highlights, shadows, and midtones
In many cases, the position or strength of the lighting at the time a photo is taken causes some areas to appear too dark and other areas to appear too light.
You can brighten or darken specific areas of an image by using the following controls
The Highlights, Shadows, and Midtones controls.
- Highlights slider — lets you adjust brightness in the lightest areas of the image; for example, if you take a photo with a flash, and the flash washes out the foreground subjects, you can move the Highlights slider to the left to darken the washed-out areas of the image. You can use the Highlights slider in conjunction with the Shadows and Midtones sliders to balance the lighting.
- Shadows slider — lets you adjust the brightness in the darkest areas of the image; for example, a bright light behind a photo subject (backlighting) at the time a photo is taken can cause the subject to appear in shadow. You can correct the photo by moving the Shadow slider to the right to lighten the dark areas and reveal more detail. You can use the Shadows slider in conjunction with the Highlights and Midtones sliders to balance the lighting.
- Midtones slider — lets you adjust the brightness of the midrange tones in the image. After adjusting the highlights and shadows, you can use the Midtones slider to fine-tune the image.
Conclusion
Now that you are familiar with some of tools and techniques you can use to create black-and-white images in Corel PHOTO-PAINT®, you can experiment with the settings to achieve various photographic effects.
For more information about the topics and tools discussed in this tutorial, refer to the Help. To access Corel PHOTO-PAINT® Help, click Help > Help topics.