#include <stdio.h>
#include <stdlib.h>
#include <gd.h>

int main()
{
	gdImagePtr im;
	FILE *pngout;
	int trans;

	im = gdImageCreate(750, 250);
	gdImageSaveAlpha(im, 1);
	trans = gdImageColorAllocateAlpha(im, 0, 0, 0, 127);
	//trans = gdImageColorAllocate(im, 0, 0, 0);
	gdImageFill(im, 0, 0, trans);

	pngout = fopen("trans.png", "w+");
	gdImagePngEx(im, pngout, 9);
	fclose(pngout);
	gdImageDestroy(im);

	return 0;
}