im_grad_x3

Usage

#include <vips/vips.h>

int im_grad_x( IMAGE *in, IMAGE *out );
int im_grad_y( IMAGE *in, IMAGE *out );

Overview

im_grad_x(3) generates an image where the value of each pixel is the difference between horizontally ajacent pixels in the input image. The output has the same height as the input and one pixel less width.

im_grad_y(3) generates an image where the value of each pixel is the difference between vertically ajacent pixels in the input image. The output has the same width as the input and one pixel less height.

In both cases, the input can be any uncoded integer type, and the output is signed 32 bit integer.

Return value

The functions returns 0 on success and -1 on error.