A program algorithm to change the values of brightness and contrast of an image, it must be simple

i need a simple program by which we can change the brightness and contrst of an image

[Steven Lord]

This sounds like a homework assignment. If it is, show us the code you've written to try to solve the problem and ask a specific question about where you're having difficulty and we may be able to provide some guidance.

If you aren't sure where to start because you're not familiar with how to write MATLAB code, I suggest you start with the free MATLAB Onramp tutorial to quickly learn the essentials of MATLAB.

If you aren't sure where to start because you're not familiar with the mathematics you'll need to solve the problem, I recommend asking your professor and/or teaching assistant for help.

Answer 1

[DGM]

The normal answer will be to use imadjust(). IPT imadjust is a basic tool for adjusting input/output levels and gamma. (5 parameters)

https://www.mathworks.com/matlabcentral/answers/528133-automatic-image-level-adjustment

If you're thinking of something simpler like a basic two-parameter brightness-contrast adjuster, and you want to write your own, see these threads:

https://www.mathworks.com/matlabcentral/answers/496452-contrast-vs-brightness-vs-gamma

https://www.mathworks.com/matlabcentral/answers/1621710-how-to-set-image-contrast-using-slider

If instead you want a two-parameter tool without having to write your own, use MIMT imbcg().

The following answer demonstrates both imadjust(), imbcg() and other related tools.

https://www.mathworks.com/matlabcentral/answers/347448-how-to-increase-the-brightness-of-an-image#answer_943225

If you want something that is interactive, there is IPT imcontrast(), which can adjust input levels, and there is MIMT immodify(), which can do various levels/gamma/contrast adjustments. I'm sure there are other tools on the File Exchange.