error using edge detection function

hi, all i have error in edgedet function my code is shown in the attaching picture please help with regards.

[anas qazaz]

Dear, Walter my picture is gray scale not true color also i try pictures gray scale in format of tiff, jpg, but the same error appear how i can use the bulit in edgedet function for gray scale images .tiff, .jpeg, .jpg regards

Answer 1

[Walter Roberson]

JPEG images are always TrueColor, and so are always 3 dimensional. You are trying to apply edge() to a 3 dimensional array, but it is restricted to 2 dimensional arrays.