sod_img sod_sobel_image(sod_img input);
Apply sobel operator on an input image. The sobel operator is very similar to Prewitt operator. It is also a derivate mask and is used for edge detection.
This works only on grayscale images. If you want to convert the colorspace of your input picture to the gray color model, call sod_grayscale_image(), sod_grayscale_image_3c() before or simply load your image from disk using the macro sod_img_load_grayscale(). A typical input image after processing should look like the following:
After Processing via sod_sobel_image()
Processed image is returned in an instance of the sod_img object. if something goes wrong during processing, then an empty image is returned via sod_make_empty_image(). Once done, you must release the memory allocated to this object via sod_free_image() to avoid memory leaks.