XAddPixel The XAddPixel() function adds a constant value to every pixel in an image. It is useful when you have a base pixel value from allocating color resources and need to manipulate the image to that form.
XDestroyImage The XDestroyImage() function deallocates the memory associated with the XImage structure. Note that when the image is created using XCreateImage(), XGetImage(), or XSubImage(), the destroy procedure that this macro calls frees both the image structure and the data pointed to by the image structure.
XGetPixel The XGetPixel() function returns the specified pixel from the named image. The pixel value is returned in normalized format (that is, the least-significant byte of the long is the least-significant byte of the pixel). The image must contain the x and y coordinates.
XPutPixel The XPutPixel() function overwrites the pixel in the named image with the specified pixel value. The input pixel value must be in normalized format (that is, the least-significant byte of the long is the least-significant byte of the pixel). The image must contain the x and y coordinates.
XSubImage The XSubImage() function creates a new image that is a subsection of an existing one. It allocates the memory necessary for the new XImage structure and returns a pointer to the new image. The data is copied from the source image, and the image must contain the rectangle defined by x, y, subimage_width, and subimage_height.