// test dct
  	image img;
  	image* output;
	readPgm(args.inFilename, &img);
	output = malloc(sizeof(img));
	int j, i, l, k;
	int h = img.h;
	int w = img.w;
	float * data;
	data = malloc (sizeof(float)*8*8);
	for(i=0; i<w; i=i+8){
		for (j=0; j<h; j=j+8){
			 dct(&img, data, i, j);
			 for(l=0;l<8;l++)
			 {
				for(k=0;k<8;k++)
				{
				 output->data[(j+l)*w +(i+k)] = (pixel_t) data[j*8+k]/8.f;
				}
			 }
		}
	}
		writePgm(args.outFilename, output);