Color management fixes

Now it's a bit more robust, tagging images with profiles when they're loaded, 
which then get interpreted later on by conversion functions. Just Linear RGB 
and sRGB profiles at the moment, same as before.

This commit fixes Martin's problem with EXRs and Multilayer images loading/
saving too dark, and it also makes the sequence editor work correctly with it too.

Also fixes:
[#19647] gamma correction with color management is reset when resetting Curve
[#19454] 2.5: Dither does not work when Color management is enabled

13 files changed, 59 insertions, 30 deletions

diff --git a/source/blender/imbuf/intern/amiga.c b/source/blender/imbuf/intern/amiga.c
index f84740826ae..91638a7ea72 100644
--- a/source/blender/imbuf/intern/amiga.c
+++ b/source/blender/imbuf/intern/amiga.c
@@ -452,6 +452,7 @@ struct ImBuf *imb_loadamiga(int *iffmem,int flags)
 	if (ibuf == 0) return (0);
 
 	ibuf->ftype = (ftype | AMI);
+	ibuf->profile = IB_PROFILE_SRGB;
 	
 	if (cmap){
 		ibuf->mincol = 0;
diff --git a/source/blender/imbuf/intern/bmp.c b/source/blender/imbuf/intern/bmp.c
index 141b8a985cf..ada5fcebf73 100644
--- a/source/blender/imbuf/intern/bmp.c
+++ b/source/blender/imbuf/intern/bmp.c
@@ -175,6 +175,7 @@ struct ImBuf *imb_bmp_decode(unsigned char *mem, int size, int flags)
 
 	if (ibuf) {
 		ibuf->ftype = BMP;
+		ibuf->profile = IB_PROFILE_SRGB;
 	}
 	
 	return(ibuf);
diff --git a/source/blender/imbuf/intern/dds/dds_api.cpp b/source/blender/imbuf/intern/dds/dds_api.cpp
index cf2f6c16d08..d7ff4761605 100644
--- a/source/blender/imbuf/intern/dds/dds_api.cpp
+++ b/source/blender/imbuf/intern/dds/dds_api.cpp
@@ -101,6 +101,7 @@ struct ImBuf *imb_load_dds(unsigned char *mem, int size, int flags)
 	if (ibuf == 0) return(0); /* memory allocation failed */
 
 	ibuf->ftype = DDS;
+	ibuf->profile = IB_PROFILE_SRGB;
 
 	if ((flags & IB_test) == 0) {
 		if (!imb_addrectImBuf(ibuf)) return(ibuf);
diff --git a/source/blender/imbuf/intern/divers.c b/source/blender/imbuf/intern/divers.c
index 35be1f716e6..bcf913e6caf 100644
--- a/source/blender/imbuf/intern/divers.c
+++ b/source/blender/imbuf/intern/divers.c
@@ -175,12 +175,14 @@ void IMB_gamwarp(struct ImBuf *ibuf, double gamma)
 }
 
 
+/* assume converting from linear float to sRGB byte */
 void IMB_rect_from_float(struct ImBuf *ibuf)
 {
 	/* quick method to convert floatbuf to byte */
 	float *tof = (float *)ibuf->rect_float;
-	float dither= ibuf->dither;
-	float srgb[3];
+	int do_dither = ibuf->dither != 0.f;
+	float dither= ibuf->dither / 255.0;
+	float srgb[4];
 	int i, channels= ibuf->channels;
 	short profile= ibuf->profile;
 	unsigned char *to = (unsigned char *) ibuf->rect;
@@ -195,7 +197,7 @@ void IMB_rect_from_float(struct ImBuf *ibuf)
 		for (i = ibuf->x * ibuf->y; i > 0; i--, to+=4, tof++)
 			to[1]= to[2]= to[3]= to[0] = FTOCHAR(tof[0]);
 	}
-	else if (profile == IB_PROFILE_SRGB) {
+	else if (profile == IB_PROFILE_LINEAR_RGB) {
 		if(channels == 3) {
 			for (i = ibuf->x * ibuf->y; i > 0; i--, to+=4, tof+=3) {
 				srgb[0]= linearrgb_to_srgb(tof[0]);
@@ -209,10 +211,26 @@ void IMB_rect_from_float(struct ImBuf *ibuf)
 			}
 		}
 		else if (channels == 4) {
-			floatbuf_to_srgb_byte(tof, to, 0, ibuf->x, 0, ibuf->y, ibuf->x);
+			if (dither != 0.f) {
+				for (i = ibuf->x * ibuf->y; i > 0; i--, to+=4, tof+=4) {
+					const float d = (BLI_frand()-0.5)*dither;
+					
+					srgb[0]= d + linearrgb_to_srgb(tof[0]);
+					srgb[1]= d + linearrgb_to_srgb(tof[1]);
+					srgb[2]= d + linearrgb_to_srgb(tof[2]);
+					srgb[3]= d + tof[3]; 
+					
+					to[0] = FTOCHAR(srgb[0]);
+					to[1] = FTOCHAR(srgb[1]);
+					to[2] = FTOCHAR(srgb[2]);
+					to[3] = FTOCHAR(srgb[3]);
+				}
+			} else {
+				floatbuf_to_srgb_byte(tof, to, 0, ibuf->x, 0, ibuf->y, ibuf->x);
+			}
 		}
 	}
-	else if(ELEM(profile, IB_PROFILE_NONE, IB_PROFILE_LINEAR_RGB) && dither==0.0f) {
+	else if(ELEM(profile, IB_PROFILE_NONE, IB_PROFILE_SRGB)) {
 		if(channels==3) {
 			for (i = ibuf->x * ibuf->y; i > 0; i--, to+=4, tof+=3) {
 				to[0] = FTOCHAR(tof[0]);
@@ -222,32 +240,26 @@ void IMB_rect_from_float(struct ImBuf *ibuf)
 			}
 		}
 		else {
-			for (i = ibuf->x * ibuf->y; i > 0; i--, to+=4, tof+=4) {
-				to[0] = FTOCHAR(tof[0]);
-				to[1] = FTOCHAR(tof[1]);
-				to[2] = FTOCHAR(tof[2]);
-				to[3] = FTOCHAR(tof[3]);
+			if (dither != 0.f) {
+				float col[3];		
+				for (i = ibuf->x * ibuf->y; i > 0; i--, to+=4, tof+=4) {
+					const float d = (BLI_frand()-0.5)*dither;
+					const float col[4] = {d+tof[0], d+tof[1], d+tof[2], d+tof[3]};
+					to[0] = FTOCHAR(col[0]);
+					to[1] = FTOCHAR(col[1]);
+					to[2] = FTOCHAR(col[2]);
+					to[3] = FTOCHAR(col[3]);
+				}
+			} else {
+				for (i = ibuf->x * ibuf->y; i > 0; i--, to+=4, tof+=4) {
+					to[0] = FTOCHAR(tof[0]);
+					to[1] = FTOCHAR(tof[1]);
+					to[2] = FTOCHAR(tof[2]);
+					to[3] = FTOCHAR(tof[3]);
+				}
 			}
 		}
 	}
-	else {
-		float dither_value, col;
-		dither= dither/255.0f;
-		for (i = ibuf->x * ibuf->y; i > 0; i--) {
-			dither_value = (BLI_frand()-0.5)*dither; 
-			col= tof[0] + dither_value;
-			to[0] = FTOCHAR(col);
-			col= tof[1] + dither_value;
-			to[1] = FTOCHAR(col);
-			col= tof[2] + dither_value;
-			to[2] = FTOCHAR(col);
-			col= tof[3] + dither_value;
-			to[3] = FTOCHAR(col);
-
-			to += 4; 
-			tof += 4;
-		}
-	}
 }
 
 void IMB_float_from_rect(struct ImBuf *ibuf)
@@ -263,8 +275,11 @@ void IMB_float_from_rect(struct ImBuf *ibuf)
 		tof = ibuf->rect_float;
 	}
 	
-	if (ibuf->profile == IB_PROFILE_SRGB) {
-		/* convert from srgb to linear rgb */
+	/* Float bufs should be stored linear */
+
+	if (ibuf->profile != IB_PROFILE_NONE) {
+		/* if the image has been given a profile then we're working 
+		 * with color management in mind, so convert it to linear space */
 		
 		for (i = ibuf->x * ibuf->y; i > 0; i--) 
 		{
diff --git a/source/blender/imbuf/intern/hamx.c b/source/blender/imbuf/intern/hamx.c
index 258c196fcdf..222604121f9 100644
--- a/source/blender/imbuf/intern/hamx.c
+++ b/source/blender/imbuf/intern/hamx.c
@@ -387,6 +387,7 @@ struct ImBuf *imb_loadanim(int *iffmem, int flags)
 	if (ibuf==0) return (0);
 
 	ibuf->ftype = (Anim | adat.type);
+	ibuf->profile = IB_PROFILE_SRGB;
 	ibuf->xorig = adat.xorig;
 	ibuf->yorig = adat.yorig;
 	ibuf->flags = flags;
diff --git a/source/blender/imbuf/intern/iris.c b/source/blender/imbuf/intern/iris.c
index 7b8c383ddb9..4389eea8939 100644
--- a/source/blender/imbuf/intern/iris.c
+++ b/source/blender/imbuf/intern/iris.c
@@ -494,6 +494,7 @@ struct ImBuf *imb_loadiris(unsigned char *mem, int flags)
 	}
 
 	ibuf->ftype = IMAGIC;
+	ibuf->profile = IB_PROFILE_SRGB;
 	if (flags & IB_ttob) IMB_flipy(ibuf);
 	
 	test_endian_zbuf(ibuf);
diff --git a/source/blender/imbuf/intern/jpeg.c b/source/blender/imbuf/intern/jpeg.c
index 2df522ff4a2..2b2d17784e2 100644
--- a/source/blender/imbuf/intern/jpeg.c
+++ b/source/blender/imbuf/intern/jpeg.c
@@ -416,6 +416,7 @@ next_stamp_marker:
 		
 		jpeg_destroy((j_common_ptr) cinfo);
 		ibuf->ftype = ibuf_ftype;
+		ibuf->profile = IB_PROFILE_SRGB;
 	}
 	
 	return(ibuf);
diff --git a/source/blender/imbuf/intern/openexr/openexr_api.cpp b/source/blender/imbuf/intern/openexr/openexr_api.cpp
index a780727b1a2..18462121810 100644
--- a/source/blender/imbuf/intern/openexr/openexr_api.cpp
+++ b/source/blender/imbuf/intern/openexr/openexr_api.cpp
@@ -933,6 +933,9 @@ struct ImBuf *imb_load_openexr(unsigned char *mem, int size, int flags)
 		
 			ibuf = IMB_allocImBuf(width, height, 32, 0, 0);
 			ibuf->ftype = OPENEXR;
+
+			/* openEXR is linear as per EXR spec */
+			ibuf->profile = IB_PROFILE_LINEAR_RGB;
 			
 			if (!(flags & IB_test))
 			{
diff --git a/source/blender/imbuf/intern/png.c b/source/blender/imbuf/intern/png.c
index 3d42eafe623..724f209884c 100644
--- a/source/blender/imbuf/intern/png.c
+++ b/source/blender/imbuf/intern/png.c
@@ -368,6 +368,7 @@ struct ImBuf *imb_loadpng(unsigned char *mem, int size, int flags)
 
 	if (ibuf) {
 		ibuf->ftype = PNG;
+		ibuf->profile = IB_PROFILE_SRGB;
 	} else {
 		printf("Couldn't allocate memory for PNG image\n");
 	}
diff --git a/source/blender/imbuf/intern/radiance_hdr.c b/source/blender/imbuf/intern/radiance_hdr.c
index 69c4970df38..5acde1232fd 100644
--- a/source/blender/imbuf/intern/radiance_hdr.c
+++ b/source/blender/imbuf/intern/radiance_hdr.c
@@ -204,6 +204,7 @@ struct ImBuf *imb_loadhdr(unsigned char *mem, int size, int flags)
 
 			if (ibuf==NULL) return NULL;
 			ibuf->ftype = RADHDR;
+			ibuf->profile = IB_PROFILE_LINEAR_RGB;
 			ibuf->xorig = ibuf->yorig = 0;
 
 			if (flags & IB_test) return ibuf;
diff --git a/source/blender/imbuf/intern/readimage.c b/source/blender/imbuf/intern/readimage.c
index 61254944001..ce3d6f9ce91 100644
--- a/source/blender/imbuf/intern/readimage.c
+++ b/source/blender/imbuf/intern/readimage.c
@@ -161,6 +161,7 @@ ImBuf *IMB_ibImageFromMemory(int *mem, int size, int flags) {
 		ibuf = imb_cocoaLoadImage((uchar *)mem, size, flags);
 		if(ibuf) {
 			ibuf->ftype = TIF;
+			ibuf->profile = IB_PROFILE_SRGB;
 			return ibuf;
 		}
 #else
diff --git a/source/blender/imbuf/intern/targa.c b/source/blender/imbuf/intern/targa.c
index acc3e06448f..9e6a774e4e5 100644
--- a/source/blender/imbuf/intern/targa.c
+++ b/source/blender/imbuf/intern/targa.c
@@ -569,6 +569,7 @@ struct ImBuf *imb_loadtarga(unsigned char *mem, int mem_size, int flags)
 
 	if (ibuf == 0) return(0);
 	ibuf->ftype = TGA;
+	ibuf->profile = IB_PROFILE_SRGB;
 	ibuf->xorig = tga.xorig;
 	ibuf->yorig = tga.yorig;
 	mem = mem + 18 + tga.numid;
diff --git a/source/blender/imbuf/intern/tiff.c b/source/blender/imbuf/intern/tiff.c
index b2465d6cc2f..0a81e903d05 100644
--- a/source/blender/imbuf/intern/tiff.c
+++ b/source/blender/imbuf/intern/tiff.c
@@ -347,6 +347,7 @@ struct ImBuf *imb_loadtiff(unsigned char *mem, int size, int flags)
 	ibuf = IMB_allocImBuf(width, height, 8*bytesperpixel, 0, 0);
 	if (ibuf) {
 		ibuf->ftype = TIF;
+		ibuf->profile = IB_PROFILE_SRGB;
 	} else {
 		fprintf(stderr, 
 			"imb_loadtiff: could not allocate memory for TIFF " \