Selective Coloring Using a DSLR Camera or GIMP
Color Keying Made Simple
If you have a color photo where you just want certain colors to show through, you have a few options on how you can make that happen.
Usually it starts with a full-color image, but there are ways you can use your DSLR to help you select only certain colors in an image.
Why use selective coloring (or color keying)? It adds a lot of interest to an image and the burst of color in an otherwise black and white image really draws your eye toward the color.
What Tools Do You Need?
Selective Coloring Using Your DSLR
If you have a DSLR camera with a "program auto" setting, you should be able to select for certain colors rather easily.
- Make sure you are in JPEG mode and not in RAW mode.
- Turn the dial on your camera to "P" for "program auto."
- Go to the menu (or select the button with a paintbrush if you have a Sony alpha-series camera). Scroll down until you get to "partial color".
- Select the color you would like the camera to detect in your image. On my particular camera, I have four color options: red, blue, green and yellow.
In the following image, I selected the color blue to pick up the blue hues from the little flower:
Have you ever tried selective coloring before?
Selective Coloring Using GIMP
If you don't have a photo editing program, don't worry! GIMP is a free program and is a great alternative to the expensive Photoshop. Although Photoshop does have some features and functions that GIMP does not, for the average person, it's a great tool.
Open your GIMP program. I will be talking about three different ways you can select for a certain color in the program, starting with the easiest way.
With this feature, you'll still be working with your image in full-color.
Use a Filter Pack
- Once you have your image opened in GIMP, you'll want to go to "colors" and down towards the bottom of the menu, you'll see "filter pack." Select it and another window will pop up.
- In the smaller window that comes up, you'll head over to "saturation" and once you've clicked on that you'll see three options: "more sat," "current," and "less sat." It should show you a preview to see what each image will look like with the different saturation levels. Select "less sat" to have the program all but desaturate the image, except for the brightest colors.
- One thing to remember about the "filter pack" is that it won't desaturate every color - only what it deems to be less bright colors and will preserve the brightest colors. Thus, if I had more colors than the blue flower in my image, it might have picked up on those colors, too.
Using a Paintbrush to Add Color In GIMP
Before you try this method, keep in mind that the colors get a little splotchy. In some images, this is fine - where you might actually want those variations in color.
In this image, however, it doesn't look that great. However, I used the same image so that you can see how the different effects work for and on the same photo.
- For this, you'll need to "desaturate" your image first. You'll need to go to the "colors" menu and then to "desaturate." You'll have three different options; select the black and white image you like the best.
- After you have desaturated your photo, you'll need to select the paintbrush tool. Then down in the paintbrush menu, select "overlay". Reduce the opacity (the little scrolling arrow directly underneath where you selected "overlay") to about 50%.
- Then, you can begin to "paint" the color on.
Using an Alpha Channel in GIMP
The last (and my favorite) option to get great selective coloring is to use an alpha channel. There are more steps involved than with the other methods; however, you can get really beautiful colors doing this. It's also very precise, allowing you to get color exactly where you want it.
- First, you'll need to open your image, still in full-color. (Look at the images below for a visual.) Go over to the right pane where it says "layers, channels, paths." If you look in the box, you'll see a little square about halfway down. Click on that to make a duplicate layer.
- Make sure that the "copied" layer is highlighted, and then go over to the "colors" menu, and then de-saturate your image.
- With that layer still highlighted, go over to "layer" and select "transparency" and then to "alpha channel."
- Move over to the left task pane (the toolbox) and select "eraser" and a brush size. Then, move over to your image and begin "erasing" the top layer so that the blue from the original image starts to show through. Continue until you are finished "coloring" what you want.
Color Keying Isn't So Bad!
Now that you know some different ways of using selective color in an image, have fun with it! You can try different things: selecting different types of paintbrushes, different colors, filters and more.
© 2013 Cynthia Calhoun