#include "gd.h"

#include <stdio.h>

#include <stdlib.h>

int main (int argc, char *argv[]) {

	FILE *fp;

	gdImagePtr in, out;

	int w, h;

	/* Help */

	if (argc<=4) {

		printf("%s  input.jpg  output.jpg  width  height\n", argv[0]);

		return 1;

	}

	/* Size */

	w = atoi(argv[3]);

	h = atoi(argv[4]);

	if (w<=0 || h<=0) {

		fprintf(stderr, "Bad size %dx%d\n", h, w);

		return 2;

	}

	/* Input */

	fp = fopen(argv[1], "rb");

	if (!fp) {

		fprintf(stderr, "Can't read image %s\n", argv[1]);

		return 3;

	}

	in = gdImageCreateFromJpeg(fp);

	fclose(fp);

	if (!in) {

		fprintf(stderr, "Can't create image from %s\n", argv[1]);

		return 4;

	}

	/* Resize */

	gdImageSetInterpolationMethod(in, GD_BILINEAR_FIXED);

	out = gdImageScale(in, w, h);

	if (!out) {

		fprintf(stderr, "gdImageScale fails\n");

		return 5;

	}

	/* Output */

	fp = fopen(argv[2], "wb");

	if (!fp) {

		fprintf(stderr, "Can't save image %s\n", argv[2]);

		return 6;

	}

	gdImageJpeg(out, fp, 90);

	fclose(fp);

	/* Cleanups */

	gdImageDestroy(in);

	gdImageDestroy(out);

	return 0;

}