Why not?

1 files changed, 163 insertions, 0 deletions

diff --git a/src/cmd/jpg/totruecolor.c b/src/cmd/jpg/totruecolor.c
new file mode 100644
index 00000000..0da5d9a3
--- /dev/null
+++ b/src/cmd/jpg/totruecolor.c
@@ -0,0 +1,163 @@
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+#include <draw.h>
+#include "imagefile.h"
+
+enum {
+	c1 = 2871,	/* 1.402 * 2048 */
+	c2 = 705,		/* 0.34414 * 2048 */
+	c3 = 1463,	/* 0.71414 * 2048 */
+	c4 = 3629,	/* 1.772 * 2048 */
+};
+
+Rawimage*
+totruecolor(Rawimage *i, int chandesc)
+{
+	int j, k;
+	Rawimage *im;
+	char err[ERRMAX];
+	uchar *rp, *gp, *bp, *cmap, *inp, *outp, cmap1[3*256];
+	int r, g, b, Y, Cr, Cb;
+
+	if(chandesc!=CY && chandesc!=CRGB24)
+		return _remaperror("remap: can't convert to chandesc %d", chandesc);
+
+	err[0] = '\0';
+	errstr(err, sizeof err);	/* throw it away */
+	im = malloc(sizeof(Rawimage));
+	if(im == nil)
+		return nil;
+	memset(im, 0, sizeof(Rawimage));
+	if(chandesc == CY)
+		im->chanlen = i->chanlen;
+	else
+		im->chanlen = 3*i->chanlen;
+	im->chandesc = chandesc;
+	im->chans[0] = malloc(im->chanlen);
+	if(im->chans[0] == nil){
+		free(im);
+		return nil;
+	}
+	im->r = i->r;
+	im->nchans = 1;
+
+	cmap = i->cmap;
+
+	outp = im->chans[0];
+
+	switch(i->chandesc){
+	default:
+		return _remaperror("remap: can't recognize channel type %d", i->chandesc);
+	case CY:
+		if(i->nchans != 1)
+			return _remaperror("remap: Y image has %d chans", i->nchans);
+		if(chandesc == CY){
+			memmove(im->chans[0], i->chans[0], i->chanlen);
+			break;
+		}
+		/* convert to three color */
+		inp = i->chans[0];
+		for(j=0; j<i->chanlen; j++){
+			k = *inp++;
+			*outp++ = k;
+			*outp++ = k;
+			*outp++ = k;
+		}
+		break;
+
+	case CRGB1:
+		if(cmap == nil)
+			return _remaperror("remap: image has no color map");
+		if(i->nchans != 1)
+			return _remaperror("remap: can't handle nchans %d", i->nchans);
+		for(j=1; j<=8; j++)
+			if(i->cmaplen == 3*(1<<j))
+				break;
+		if(j > 8)
+			return _remaperror("remap: can't do colormap size 3*%d", i->cmaplen/3);
+		if(i->cmaplen != 3*256){
+			/* to avoid a range check in loop below, make a full-size cmap */
+			memmove(cmap1, cmap, i->cmaplen);
+			cmap = cmap1;
+		}
+		inp = i->chans[0];
+		if(chandesc == CY){
+			for(j=0; j<i->chanlen; j++){
+				k = *inp++;
+				r = cmap[3*k+2];
+				g = cmap[3*k+1];
+				b = cmap[3*k+0];
+				r = (2125*r + 7154*g + 721*b)/10000;	/* Poynton page 84 */
+				*outp++ = r;
+			}
+		}else{
+			for(j=0; j<i->chanlen; j++){
+				k = *inp++;
+				*outp++ = cmap[3*k+2];
+				*outp++ = cmap[3*k+1];
+				*outp++ = cmap[3*k+0];
+			}
+		}
+		break;
+
+	case CRGB:
+		if(i->nchans != 3)
+			return _remaperror("remap: can't handle nchans %d", i->nchans);
+		rp = i->chans[0];
+		gp = i->chans[1];
+		bp = i->chans[2];
+		if(chandesc == CY){
+			for(j=0; j<i->chanlen; j++){
+				r = *bp++;
+				g = *gp++;
+				b = *rp++;
+				r = (2125*r + 7154*g + 721*b)/10000;	/* Poynton page 84 */
+				*outp++ = r;
+			}
+		}else
+			for(j=0; j<i->chanlen; j++){
+				*outp++ = *bp++;
+				*outp++ = *gp++;
+				*outp++ = *rp++;
+			}
+		break;
+
+	case CYCbCr:
+		if(i->nchans != 3)
+			return _remaperror("remap: can't handle nchans %d", i->nchans);
+		rp = i->chans[0];
+		gp = i->chans[1];
+		bp = i->chans[2];
+		for(j=0; j<i->chanlen; j++){
+			Y = *rp++ << 11;
+			Cb = *gp++ - 128;
+			Cr = *bp++ - 128;
+			r = (Y+c1*Cr) >> 11;
+			g = (Y-c2*Cb-c3*Cr) >> 11;
+			b = (Y+c4*Cb) >> 11;
+			if(r < 0)
+				r = 0;
+			if(r > 255)
+				r = 255;
+			if(g < 0)
+				g = 0;
+			if(g > 255)
+				g = 255;
+			if(b < 0)
+				b = 0;
+			if(b > 255)
+				b = 255;
+			if(chandesc == CY){
+				r = (2125*r + 7154*g + 721*b)/10000;
+				*outp++ = r;
+			}else{
+				*outp++ = b;
+				*outp++ = g;
+				*outp++ = r;
+			}
+		}
+		break;
+	}
+	return im;
+}