read color data at one pixel

Hello everyone, I need to read the data of an image into an array. My array is a 3-dimension array, first dimension is the width corresponding to the width of the image, second dimension is the height . The third dimesion is the Color Depth of the image, I convert image color format to 24bit RGB ( 3 bytes -> 3 elements for each width and height coordinate). The problem is how to read the color data at each pixel of an image ? I tried some properties of Image class but can't find the way out. Please help, thanks.