C / C++ / MFC

bool JPEGCompressMono(FILE* Out,int Quality,unsigned char* pSrc,int Width,int Height)
{
	struct jpeg_compress_struct cinfo;
	struct jpeg_error_mgr err; // you'll usually want to use your own error handling instead
	cinfo.err = jpeg_std_error(&err);
	jpeg_create_compress(&cinfo);
	jpeg_stdio_dest(&cinfo,Out);
	cinfo.image_width=Width;
	cinfo.image_height=Height;
	cinfo.input_components=1;
	cinfo.in_color_space=JCS_GRAYSCALE;
//	cinfo.write_JFIF_header=1; // you can add all sorts of extra info if you want
	jpeg_set_defaults(&cinfo);
	jpeg_set_quality(&cinfo,Quality,TRUE);
	jpeg_start_compress(&cinfo,TRUE);
	int Slop=(Width%4)?4-Width%4:0;
	JSAMPROW row_pointer[1];
	while (cinfo.next_scanline < cinfo.image_height)
	{
		row_pointer[0]=pSrc+(Height-1-cinfo.next_scanline)*(Width+Slop);
		jpeg_write_scanlines(&cinfo,row_pointer,1);
	}
	jpeg_finish_compress(&cinfo);
	jpeg_destroy_compress(&cinfo);
	return true;
}