Power Generator
Imaging Lens
Image Sensor
Polyoptic Wheel
Viewfinder, Eye
LED Flash
LCD Display
Image Processing

Downloadable PDFs

Introduction      Representation      Processing      Brightness
Noise      Warping      Illustrations

How is an Image Processed?

Figure 4: How an image is processed

Most image processing operations follow a simple procedure. Given an input image, the output image is calculated one pixel at a time. The color at each pixel in the output image is usually some mathematical combination of colors of pixels within a small neighborhood (window) centered on the same pixel in the input image. In some cases, instead of a neighborhood of pixels just the corresponding pixel in the input image is used.

The demo in Figure 4 helps you visualize the above process. The output image is computed one pixel at a time from left to right and top to bottom. In this example, the color of each pixel is calculated using a small window of 3 × 3 pixels centered on the corresponding pixel in the input image. In the following sections, we will describe how three widely used image processing operations work.