are there any index in image processing toolbox of matlab that would represent intensity of an image?

I want to know wheter there is some functions in matlab which would describe the intensity of an image. I want to study different intensity image with some parameters like g channel and to see how the intensity result differs with different values of parameters obtained.

Answer 1

[Image Analyst]

The value of the image matrix is its intensity. A color image has three color channels (usually) and each color channel has its own intensity. You can get the intensity of a single pixel, some group of pixels, or of the entire image. I'm not really sure how to answer your question because I don't know what you want to measure. There is no function that "describes" the intensity unless you mean imhist(), or mean2(), or max() or min() - that sort of thing. But I'm sure you already know about those functions.

Answer 2

[Walter Roberson]

If you mean brightness, then rgb2gray()

Note: The rgb2gray() calculations are linear in each of the channels (with different coefficients for each channel), so you could use theory rather than experiments.