#4 – No Fibonacci Here – The AdjustChannelCommand
Too much blue? Not enough blue? Get rid of blue altogether? The AdjustChannelCommand lets you manually adjust the colors in your image by adjusting the channels. It is available for DotImage Photo, Photo Pro, and Document Imaging.
The command lets you adjust the 3 color channels, plus the alpha channel (which is helpful if you are trying to overlay one image onto another). You can adjust by percentage (-100 to 100) or by a fixed value (-255 to 255). A value of 0 does nothing. Also, you can adjust all channels at once.
By the way, you need to have a color image. I don’t want to hear complaints if you are trying to adjust the red channels on a black and white image. That’s just silly.
This is also our first command to introduce the Region of Interest. Using a rectangle, you can select only part of the image to adjust, as I’ve done in the example below. This feature requires a Photo Pro or Document Imaging license.
Properties to play with:
- AdjustByPercentage – Set to ‘True’, you adjust by percentages. Set to ‘False’, you adjust by a literal value.
- Channel1 – the Red Channel
- Channel2 – the Green Channel
- Channel3 – the Blue Channel
- Channel4 – the Alpha Channel
- RegionOfInterest – If you don’t set this, your entire image will be processed.
Before:
After (with a RegionOfInterest set and Channel2 = –100, reducing the green):
Also, and let me write this in big, sparkly letters – THIS COMMAND PERFORMS IN-PLACE! When you run this command, you will change your image. If you want to keep your original command intact, make a clone of it to run the command on.
Tomorrow is the AdjustHslCommand, which is going to look a lot like today.