GIMP stands for Gnu Image Manipulation Program. It is a free, open-source graphics and image editing software that works on all major computer operating systems. The term "16-bit" describes the number of different unique colors a program is capable of handling when it edits an image. GIMP has some very professional features, but it does not support 16-bit color editing.
8-Bit Color vs. 16-Bit Color
- On computer screens, colors are configured using shades of red, green and blue, called RGB color. 8-bit and 16-bit are two common ways to measure the number of different colors in a digital image. "Bit" is a computer term that equals 2. The 8 and 16 are the powers of 2 equaling the number of shades each of red, green and blue available in the image format. Two to the eighth power is 8-bit color, which equals 256 shades. Two to the sixteenth power is 16-bit color, which calculates out to 65,536 shades. This means that 8-bit color has the potential to show 16.8 million colors, while 16-bit color can portray 281 trillion colors.
GIMP and 8-Bit Color
- GIMP has many professional features similar to those found in Adobe Photoshop and other professional graphics software. But GIMP supports a maximum of 8-bit color, which is the number of colors supported in the JPEG image format. This means that 16-bit color editing is not possible using GIMP, but if you are dealing with JPEG images, you are only dealing with 8-bit images anyway.
Why It Matters
- Presented with a side-by-side comparison of an 8-bit and 16-bit version of the same photo, the human eye will not see much difference between them. So it might seem that it's unimportant that GIMP does not support 16-bit color. And for some types of graphic work, this is true. However, the greater color depth of a 16-bit color image gives you room to make some edits without risking that they will show up clearly in the final image. An example of this is using the clone tool to fix a problem in an area of the photo. Another example is that an area that shows up as a smooth gradient, fading from one color to another gradually in the 16-bit color image might show up with bands of colors instead.
Alternatives
- If you do a lot of photo editing with 16-bit color images, you won't be able to do so using GIMP. The most well-known alternative to GIMP is Adobe Photoshop. This is an expensive software program, and it has a somewhat steep learning curve. Another alternative is Corel's PaintShop Pro X4 or above, which also supports 16-bit color.
