In the early days of the Internet, small file sizes where an important consideration in website design, as most people could only get online using slow dial-up connections. Today, the increasing availability of fast broadband connections makes file size less of an issue. Designers who want to use smaller image sizes can do so by reducing the size and resolution of the image, as well as reducing the number of colors. Using free image-editing software such as GIMP, you can quickly convert images from the standard RGB color format to a color depth of 16 colors.
Open an image by clicking "File," then "Open" and browsing to the image. Click "Open" on the Open Image window after selecting the image.
Click "Image," then "Mode," then click "Indexed ..." On the Indexed Color Conversion window, click "Generate optimum palette" if it is not already selected, then enter 16 in the box next to "Maximum number of colors."
Click "Convert." After GIMP finishes converting the image, click "File," then "Save As..." to save the image.
Tips & Warnings
- Using 16 colors is not recommended for digital photos, as it will distort how the image appears. A 16-color depth is best used for images with few colors, such as navigation buttons.