An implementation of the Sobel operator for edge detection in images. Below there is an example of taking the first image and having the calculated image bellow.

sobel file_in file_out 123x456 [-i file_h_out file_v_out] [-g file_gray]

The file_in and file_out arguments are, obvious, the file for which the contour should be calculated and the file with that calculated contour, respectively. The third argument is the size of the image (width x height). It is needed because the RGB file type does not contain any meta information about the image it self.

The optional arguments are:

-i - Generate intermediate files with the result of the vertical and horizontal operators.

-g - Generate the gray scale file.

To simply compile and execute the example you can execute the following command:

make clean all test

The test rule of the Makefile will copy to the HERO emulator the example pictures stored in the directory IMG_DIR and it will copy back after the execution on the folder IMG_DIR_OUT. User can change such directories properly.

User can control the application arguments, image folder name, and picture file name changing the environment setup on the Makefile.