The ImageProcessingDemo Program

I wrote a simple program named ImageProcessingDemo to demonstrate these concepts. You can download the code here. When the program first runs, it displays a default image that can be found in the program directory as shown in the figure below. You can click the browse button if you want to load a different image.

There are only four operations that can be performed on an image: darken, lighten, restore, and invert. The button with the '<' character darkens the image a bit. The button with the '>' character lightens the image a bit. The button with the 'R' character restores the image to its original state. And finally the button with the 'I' character inverts the image.

Before jumping into the processing code, we need to talk about BMP headers and the data format. BMP files have two headers: the file header and the information header. The file header is the first 14 bytes of the BMP file and contains the string 'BM', a long specifying the size of the file in bytes, two reserved words that must have a value of 0, and finally the offset from the beginning of the file to where the actual image data is. The following chart shows the BMP file header.

The information header contains information about the bitmap including its size, width, height, and format. The following chart shows the BMP information header.