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Contrast Adjustment

Contrast adjustment, histogram equalization, decorrelation stretching

Functions

imadjust Adjust image intensity values or colormap
imcontrast Adjust Contrast tool
imsharpen Sharpen image using unsharp masking
locallapfilt Fast Local Laplacian Filtering of images
localcontrast Edge-aware local contrast manipulation of images
localtonemap Render HDR image for viewing while enhancing local contrast
histeq Enhance contrast using histogram equalization
adapthisteq Contrast-limited adaptive histogram equalization (CLAHE)
imhistmatch Adjust histogram of 2-D image to match histogram of reference image
imhistmatchn Adjust histogram of N-D image to match histogram of reference image
decorrstretch Apply decorrelation stretch to multichannel image
stretchlim Find limits to contrast stretch image
intlut Convert integer values using lookup table
imnoise Add noise to image

Examples and How To

Adjust Image Contrast In Image Viewer App

To adjust image contrast in the Image Viewer app, use the Adjust Contrast tool.

Adjust Image Intensity Values to Specified Range

This example shows how to increase the contrast in a grayscale image by remapping the data values to fill the entire available intensity range [0, 255].

Histogram Equalization

Histogram equalization adjusts image intensity automatically by mapping the histogram of the output images to a specified histogram.

Adaptive Histogram Equalization

Adaptive histogram equalization adjusts image intensity in small regions in the image.

Enhance Color Separation Using Decorrelation Stretching

Decorrelation stretching enhances the color separation of an image to improve visual interpretation and make feature discrimination easier.

Correct Nonuniform Background Illumination and Analyze Foreground Objects

This example shows how to enhance an image as a preprocessing step before analysis.

Concepts

Contrast Adjustment

Contrast adjustment remaps image intensity values.

Understanding Contrast Adjustment

Contrast adjustment remaps image data values to the full display range of the data type.

Gamma Correction

Gamma correction allows for nonlinear contrast adjustment.

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