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Converting a color image to black and white by using desaturation command is probably the easiest way of changing color mode next to direct conversion (image>mode>grayscale). Easy as ABC, this option also has its downside: it can be less effective because you do not have much control over the process. However, this can be used when you simply need a black and white photo without paying much attention to details.

Here’s how:

1. Open the image file that you need to convert into B&W.

2. On the “Image” menu, click on “Adjustments” then select “Desaturate”.

3. To complete the process, click again the “Image” menu, “Mode” then choose “Grayscale”.

Every RGB image in Photoshop consists of three 8-bit or 12-bit (grayscale) color channers: red, green, and blue. One way of converting a color image to Black-and-white is to extract one of the color channels-the one with the best B&W contrast-into separte B&W file.

1. Open the image you want to convert into B&W.

2. Go to the “Channels” palette and compare the different channels to find out which B&W version you prefer. Click on the thumbnail of each channel so only that channel will be visible.

3. Delete the channels that you don’t need. Simply drag and drop them to the “trashcan” icon located just below the “Channels” window. Click the “OK” button should a dialogue box appear (confirming to flatten layers). Doing this will immediately transform the image into a “Multichannel” document and the name of the remaining channel is changed to its opposite color. Choosing green will give you magenta.

4. Finally, you have to convert the “Multichannel” document to “Grayscale” mode to complete the process. Go to “Image” menu, choose “Mode” and select “Grayscale”.

See illustrations below