Upload an image if you want further advice. For certain other cases (radiology and fluorescence) you should do subtraction. For an input A that contains symbolic expression, the symbolic max function returns an unevaluated expression that is reduced by eliminating arguments that do not represent maximum values. If A is a matrix, then max(A) is a row vector containing the maximum value of each column.

Finally, division is the right way to do it in most cases. If A is a vector, then max(A) returns the maximum of A. Do you have a uniform background that you can image? Or all you have is the image with your scene and illumination combined? If, unfortunately, you have the latter case, you can either try homomorphic filtering (basically assuming the light pattern is a very low pass filtered version of your scene) or try to find 'holes' in your scene that is pure background and then try to fit a nice smooth model, like a 2D polynomial, to them. But even then, there are flaws with that method such that you will increase the noise and have quantization/posterization errors. For example, islocalmin (A,2) finds the local minimum of each row of a matrix A. i want to apply a sliding window minimum filter on input image I and obtain Imin and also apply sliding window maximum filter on Imin to obtain Imax : the following is code. The output may have another argument that represents the condition for the symbolic variable. Set of functions to look for local minima or maxima in a vector, find a point inside a vector closest to a certain value and small function to clear.

TF islocalmin (A,dim) specifies the dimension of A to operate along. For an input A that contains symbolic expression, the symbolic max function returns an unevaluated expression that is reduced by eliminating arguments that do not represent maximum values. I do background correction all the time and this would not be a good way of getting the background unless your background was uniform and had small light-colored dust on it. TF islocalmin (A) returns a logical array whose elements are 1 ( true) when a local minimum is detected in the corresponding element of A. It is not a way to get the illumination pattern that I've ever heard of. For example, you can obtain a discrete design by specifying Smooth,off. Doing a max filter on the output of the min filter is called a morphological opening and is done by imopen(). find Find local min and max values of experimental data with Matlab.

Find local min and max matlab