This tool converts JPG photos to a grayscale version by removing all color information from the photo. There are many different ways to convert color components to grayscale and this tool supports the three most popular methods: "BT-709 (HDTV)", "BT-601 (PAL/NTSC)", and "Average Red, Green, Blue". The BT-709 grayscale method is the most common method for converting colors to grayscale. It's used in high-definition TVs and other modern digital video standards. The BT-601 grayscale method is similar to the BT-709 method, but it uses slightly different weights for red, green, and blue color channels. It's used in regular broadcast television in most countries around the world. The average component grayscale method is the simplest way to convert colors to grayscale. It simply computes the average value of the three color components (red, green, and blue) and uses this value as the grayscale value. For a more advanced JPG to grayscale conversion, you can enable the custom grayscale checkbox option and create your own conversion method by specifying coefficients for the red, green, and blue channels. In addition to these options, there is an additional option to limit the number of colors in the output JPG. This parameter allows you to create a grayscale JPG with a specific number of gray shades (for example, 30, 15, 5, or even just 2). Jpgabulous!