jpg(1), jpg: add -y flag to usage

png: colorspace will never be CYCbCr (this is no
doubt from copy-pasting from jpg)

tif: everyone else uses colorspace as a function
argument, so we will too

readtif, writetif: credit paul bourke

sys/man/1/jpg

@@ -4,7 +4,7 @@ jpg, gif, png, tif, ppm, bmp, v210, yuv, ico, tga, tojpg, togeordi, togif, toppm
 .SH SYNOPSIS
 .B jpg
 [
-.B -39cdefFkJrtv
+.B -39cdefFkJrtvy
 ] [
 .I file ...
 ]

sys/src/cmd/jpg/imagefile.h

@@ -53,8 +53,8 @@ Rawimage**	readjpg(int, int);
 Rawimage**	Breadjpg(Biobuf*, int);
 Rawimage**	readpng(int, int);
 Rawimage**	Breadpng(Biobuf*, int);
-Rawimage**	readtif(int);
-Rawimage**	Breadtif(Biobuf*);
+Rawimage**	readtif(int, int);
+Rawimage**	Breadtif(Biobuf*, int);
 Rawimage**	readgif(int, int);
 Rawimage**	readpixmap(int, int);
 Rawimage*	torgbv(Rawimage*, int);

sys/src/cmd/jpg/jpg.c

@@ -110,7 +110,7 @@ main(int argc, char *argv[])
 			outchan = CMAP8;
 		break;
 	default:
-		fprint(2, "usage: jpg -39cdefFkJrtv [file.jpg ...]\n");
+		fprint(2, "usage: jpg -39cdefFkJrtvy [file.jpg ...]\n");
 		exits("usage");
 	}ARGEND;
 

sys/src/cmd/jpg/png.c

@@ -11,7 +11,6 @@ int	dflag = 0;
 int	eflag = 0;
 int	nineflag = 0;
 int	threeflag = 0;
-int	colorspace = CRGB;
 int	output = 0;
 ulong	outchan = CMAP8;
 Image	*image;
@@ -48,7 +47,6 @@ main(int argc, char *argv[])
 {
 	int fd, i;
 	char *err;
-	char buf[12+1];
 
 	ARGBEGIN{
 	case 'c':		/* produce encoded, compressed, bitmap file; no display by default */
@@ -71,9 +69,6 @@ main(int argc, char *argv[])
 		defaultcolor = 0;
 		outchan = GREY8;
 		break;
-	case 'r':
-		colorspace = CRGB;
-		break;
 	case '3':		/* produce encoded, compressed, three-color bitmap file; no display by default */
 		threeflag++;
 		/* fall through */
@@ -100,16 +95,6 @@ main(int argc, char *argv[])
 		exits("usage");
 	}ARGEND;
 
-	if(dflag==0 && colorspace==CYCbCr){	/* see if we should convert right to RGB */
-		fd = open("/dev/screen", OREAD);
-		if(fd > 0){
-			buf[12] = '\0';
-			if(read(fd, buf, 12)==12 && chantodepth(strtochan(buf))>8)
-				colorspace = CRGB;
-			close(fd);
-		}
-	}
-
 	err = nil;
 	if(argc == 0)
 		err = show(0, "<stdin>", outchan);
@@ -146,7 +131,7 @@ show(int fd, char *name, int outc)
 	if(Binit(&b, fd, OREAD) < 0)
 		return nil;
 	outchan = outc;
-	array = Breadpng(&b, colorspace);
+	array = Breadpng(&b, CRGB);
 	if(array == nil || array[0]==nil){
 		fprint(2, "png: decode %s failed: %r\n", name);
 		return "decode";

sys/src/cmd/jpg/readtif.c

@@ -1,12 +1,14 @@
 /*
 * code/documentation:
 * http://partners.adobe.com/public/developer/en/tiff/TIFF6.pdf
-* http://paulbourke.net/dataformats/tiff/
 * http://www.fileformat.info/format/tiff/egff.htm
 * http://www.fileformat.info/mirror/egff/ch09_05.htm
 * http://www.itu.int/rec/T-REC-T.4-199904-S/en
 * http://www.itu.int/rec/T-REC-T.6-198811-I/en
 *
+* many thanks to paul bourke for a simple description of tiff:
+* http://paulbourke.net/dataformats/tiff/
+*
 * copy-pasted fax codes and lzw help:
 * http://www.remotesensing.org/libtiff/
 */
@@ -1797,11 +1799,16 @@ readslave(Tif *t)
 }
 
 Rawimage **
-Breadtif(Biobuf *b)
+Breadtif(Biobuf *b, int colorspace)
 {
 	Rawimage **array, *r;
 	Tif *t;
 
+	if(colorspace != CRGB24) {
+		werrstr("unknown color space: %d",
+			colorspace);
+		return nil;
+	}
 	if((t = malloc(sizeof *t)) == nil)
 		return nil;
 	if((array = malloc(2*sizeof *array)) == nil)
@@ -1842,14 +1849,14 @@ Breadtif(Biobuf *b)
 }
 
 Rawimage **
-readtif(int fd)
+readtif(int fd, int colorspace)
 {
 	Rawimage **a;
 	Biobuf b;
 
 	if(Binit(&b, fd, OREAD) < 0)
 		return nil;
-	a = Breadtif(&b);
+	a = Breadtif(&b, colorspace);
 	Bterm(&b);
 	return a;
 }

sys/src/cmd/jpg/tif.c

@@ -165,7 +165,7 @@ show(int fd, char *name, int outchan)
 
 	if(Binit(&b, fd, OREAD) < 0)
 		return nil;
-	array = Breadtif(&b);
+	array = Breadtif(&b, CRGB24);
 	if(array == nil || array[0] == nil) {
 		if(array != nil)
 			free(array);

sys/src/cmd/jpg/writetif.c

@@ -1,12 +1,14 @@
 /*
 * code/documentation:
 * http://partners.adobe.com/public/developer/en/tiff/TIFF6.pdf
-* http://paulbourke.net/dataformats/tiff/
 * http://www.fileformat.info/format/tiff/egff.htm
 * http://www.fileformat.info/mirror/egff/ch09_05.htm
 * http://www.itu.int/rec/T-REC-T.4-199904-S/en
 * http://www.itu.int/rec/T-REC-T.6-198811-I/en
 *
+* many thanks to paul bourke for a simple description of tiff:
+* http://paulbourke.net/dataformats/tiff/
+*
 * copy-pasted fax codes and copy-pasted lzw encoding
 * hash table implementation:
 * http://www.remotesensing.org/libtiff/