use matlab help imread IMREAD Read image from graphics file. A = IMREAD(FILENAME,FMT) reads the image in FILENAME into A. If the file contains a grayscale intensity image, A is a two-dimensional array. If the file contains a truecolor (RGB) image, A is a three-dimensional (M-by-N-by-3) array. FILENAME is a string that specifies the name of the graphics file, and FMT is a string that specifies the format of the file. The file must be in the current directory or i