histogramomvandling

Histogramomvandling is a digital image processing technique used to adjust the contrast of an image by modifying the intensity values of its pixels. The goal is to redistribute the pixel intensities so that they cover a wider range of the available intensity levels, thereby enhancing the contrast and making details more visible. This is achieved by transforming the image's histogram, which is a graphical representation of the distribution of pixel intensities.

The process typically involves calculating the cumulative distribution function (CDF) of the image's histogram. The CDF at a particular intensity level represents the proportion of pixels with intensities less than or equal to that level. This CDF is then used to map the original pixel intensities to new intensity values. The transformation function ensures that the new intensity values are spread out more evenly across the entire possible range, from the minimum to the maximum intensity.

A common form of histogramomvandling is called histogram equalization. In histogram equalization, the aim is to produce an output image with a uniform histogram, meaning all intensity levels have approximately the same number of pixels. This is ideal for images where the intensity distribution is highly skewed, leading to poor contrast in certain areas. While powerful for enhancing contrast, histogramomvandling can sometimes introduce undesirable artifacts or alter the natural appearance of an image if applied too aggressively. It is a fundamental technique in image enhancement, often used as a preprocessing step before other image analysis tasks.