Function PSL_plotcolorimage

src/postscriptlight.c:3848–3932

}

int PSL_plotcolorimage (struct PSL_CTRL *PSL, double x, double y, double xsize, double ysize, int justify, unsigned char *buffer, int nx, int ny, int nbits) {
	/* Plots a 24-bit color image in Grayscale, RGB or CMYK mode.
	 * When the number of unique colors does not exceed PSL_MAX_COLORS, the routine will index
	 * 24-bit RGB images and then attempt to reduce the depth of the indexed image to 1, 2 or 4 bits.
	 *
	 * x, y		: lower left position of image in plot units
	 * xsize, ysize	: image size in units (if 0, adjust to keep the original aspect ratio)
	 * justify	: indicates what corner x,y refers to (see graphic below)
	 * buffer	: contains the bytes for the image
	 * nx, ny	: pixel dimension
	 * nbits	: number of bits per pixel (1, 2, 4, 8, 24)
	 *
	 * Special cases:
	 * nx < 0	: 8- or 24-bit image contains a color mask (first 1 or 3 bytes)
	 * nbits < 0	: "Hardware" interpolation requested
	 *
	 *   9       10      11
	 *   |----------------|
	 *   5    <image>     7
	 *   |----------------|
	 *   1       2        3
	 */
	int id, it;
	const char *colorspace[3] = {"Gray", "RGB", "CMYK"};			/* What kind of image we are writing */
	const char *decode[3] = {"0 1", "0 1 0 1 0 1", "0 1 0 1 0 1 0 1"};	/* What kind of color decoding */
	const char *type[3] = {"1", "4 /MaskColor[0]", "1 /Interpolate true"};
	psl_indexed_image_t image;

	/* If one of [xy]size is 0, keep the aspect ratio */
	if (PSL_eq (xsize, 0.0)) xsize = (ysize * nx) / ny;
	if (PSL_eq (ysize, 0.0)) ysize = (xsize * ny) / nx;

	/* Correct origin (x,y) in case of justification */
	if (justify > 1) {      /* Move the new origin so (0,0) is lower left of box */
		x -= 0.5 * ((justify + 3) % 4) * xsize;
		y -= 0.5 * (int)(justify / 4) * ysize;
	}

	/* Gray scale, CMYK or RGB encoding/colorspace */
	id = (PSL->internal.color_mode == PSL_GRAY || abs (nbits) < 24) ? 0 : (PSL->internal.color_mode == PSL_CMYK ? 2 : 1);
	/* Colormask or interpolate */
	it = nx < 0 ? 1 : (nbits < 0 ? 2 : 0);

	if (PSL->internal.color_mode != PSL_GRAY && (image = psl_makecolormap (PSL, buffer, nx, ny, nbits))) {
		/* Creation of colormap was successful */
		nbits = psl_bitreduce (PSL, image->buffer, nx, ny, image->colormap->ncolors);

		PSL_comment (PSL, "Start of indexed %s image [%d bit]\n", colorspace[id], nbits);
		PSL_command (PSL, "V N %d %d T %d %d scale [/Indexed /Device%s %" PRIuS " <\n", psl_ix(PSL, x), psl_iy(PSL, y), psl_iz (PSL, xsize), psl_iz (PSL, ysize), colorspace[id], image->colormap->ncolors - 1);
		psl_stream_dump (PSL, &image->colormap->colors[0][0], (int)image->colormap->ncolors, 1, 24, 0, PSL_HEX, 2);
		PSL_command (PSL, ">] setcolorspace\n<< /ImageType %s /Decode [0 %d] ", type[it], (1<<nbits)-1);
		psl_stream_dump (PSL, image->buffer, nx, ny, nbits, PSL->internal.compress, PSL_ASCII85, 0);
		PSL_command (PSL, "U\n");
		PSL_comment (PSL, "End of indexed %s image\n", colorspace[id]);

		/* Clear the newly created image buffer and colormap */
		PSL_free (image->buffer);
		PSL_free (image->colormap);