What is the difference between 'image normalization', 'contrast stretching' and 'histogram equalization'?

1. What is the difference between contrast stretching and histogram equalization?
2. What is the difference between histogram equalization and histogram normalization?
3. What is contrast stretching in image processing?
4. What is histogram stretching in image processing?

What is the difference between contrast stretching and histogram equalization?

In Histogram equalization, you want to flatten the histogram into a uniform distribution. In contrast stretching, you manipulate the entire range of intensity values. Like what you do in Normalization. Note that contrast stretching is also called Histogram stretching.

What is the difference between histogram equalization and histogram normalization?

The equalize will attempt to produce a histogram with equal amounts of pixels in each intensity level. This can produce unrealistic images since the intensities can be radically distorted but can also produce images very similar to normalization which preserves relative levels which the equalization process does not.

What is contrast stretching in image processing?

Contrast stretching (often called normalization) is a simple image enhancement technique that attempts to improve the contrast in an image by 'stretching' the range of intensity values it contains to span a desired range of values, the full range of pixel values that the image type concerned allows.

What is histogram stretching in image processing?

Histogram stretching involves modifying the brightness (intensity) values of pixels in the image according to some mapping function that specifies an output pixel brightness value for each input pixel brightness value. For a grayscale digital image, this process is straightforward.