This digitization procedure can be done by a scanner, or by a video camera connected to a frame grabber board in a computer. Once the image has been digitized, it can be operated upon by various image processing operations. Image processing operations can be roughly divided into three major categories, Image Compression , Image Enhancement and Restoration , and Measurement Extraction .
Image compression is familiar to most people.
It involves reducing the amount of memory needed to store a digital image. Once the image is in good condition, the Measurement Extraction operations can be used to obtain useful information from the image. Some examples of Image Enhancement and Measurement Extraction are given below. The examples shown all operate on 256 grey-scale images. These operations can be extended to operate on colour images.