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

23 files changed, 166 insertions, 82 deletions

diff --git a/source/blender/blenkernel/BKE_image.h b/source/blender/blenkernel/BKE_image.h
index 7f18fb1624d..6b8d9d1768e 100644
--- a/source/blender/blenkernel/BKE_image.h
+++ b/source/blender/blenkernel/BKE_image.h
@@ -143,6 +143,9 @@ struct RenderPass *BKE_image_multilayer_index(struct RenderResult *rr, struct Im
 struct RenderResult *BKE_image_acquire_renderresult(struct Scene *scene, struct Image *ima);
 void BKE_image_release_renderresult(struct Scene *scene, struct Image *ima);
 
+/* frees all ibufs used by any image datablocks */
+void	BKE_image_free_image_ibufs(void);
+	
 /* goes over all textures that use images */
 void	BKE_image_free_all_textures(void);
 
diff --git a/source/blender/blenkernel/intern/colortools.c b/source/blender/blenkernel/intern/colortools.c
index cd8c0c24087..d8975c16cc8 100644
--- a/source/blender/blenkernel/intern/colortools.c
+++ b/source/blender/blenkernel/intern/colortools.c
@@ -763,10 +763,16 @@ void colorcorrection_do_ibuf(ImBuf *ibuf, const char *profile)
 	}
 }
 
-
+/* only used for image editor curves */
 void curvemapping_do_ibuf(CurveMapping *cumap, ImBuf *ibuf)
 {
+	ImBuf *tmpbuf;
 	int pixel;
+	char *tmpcbuf;
+	float *pix_in;
+	float col[3];
+	int stride= 4;
+	float *pix_out;
 	
 	if(ibuf==NULL)
 		return;
@@ -775,35 +781,45 @@ void curvemapping_do_ibuf(CurveMapping *cumap, ImBuf *ibuf)
 	else if(ibuf->rect==NULL)
 		imb_addrectImBuf(ibuf);
 	
+	if (!ibuf->rect || !ibuf->rect_float)
+		return;
+	
+	/* work on a temp buffer, so can color manage afterwards.
+	 * No worse off memory wise than comp nodes */
+	tmpbuf = IMB_dupImBuf(ibuf);
+	
 	curvemapping_premultiply(cumap, 0);
 	
-	if(ibuf->rect_float && ibuf->rect) {
-		float *pixf= ibuf->rect_float;
-		float col[3];
-		int stride= 4;
-		char *pixc= (char *)ibuf->rect;
-		
-		if(ibuf->channels)
-			stride= ibuf->channels;
-		
-		for(pixel= ibuf->x*ibuf->y; pixel>0; pixel--, pixf+=stride, pixc+=4) {
-			if(stride<3) {
-				col[0]= curvemap_evaluateF(cumap->cm, *pixf);
-				pixc[1]= pixc[2]= pixc[3]= pixc[0]= FTOCHAR(col[0]);
-			}
-			else {
-				curvemapping_evaluate_premulRGBF(cumap, col, pixf);
-				pixc[0]= FTOCHAR(col[0]);
-				pixc[1]= FTOCHAR(col[1]);
-				pixc[2]= FTOCHAR(col[2]);
-				if(stride>3)
-					pixc[3]= FTOCHAR(pixf[3]);
-				else
-					pixc[3]= 255;
-			}
+	pix_in= ibuf->rect_float;
+	pix_out= tmpbuf->rect_float;
+//	pixc= (char *)ibuf->rect;
+	
+	if(ibuf->channels)
+		stride= ibuf->channels;
+	
+	for(pixel= ibuf->x*ibuf->y; pixel>0; pixel--, pix_in+=stride, pix_out+=4) {
+		if(stride<3) {
+			col[0]= curvemap_evaluateF(cumap->cm, *pix_in);
+			
+			pix_out[1]= pix_out[2]= pix_out[3]= pix_out[0]= col[0];
+		}
+		else {
+			curvemapping_evaluate_premulRGBF(cumap, col, pix_in);
+			pix_out[0]= col[0];
+			pix_out[1]= col[1];
+			pix_out[2]= col[2];
+			if(stride>3)
+				pix_out[3]= pix_in[3];
+			else
+				pix_out[3]= 1.f;
 		}
 	}
 	
+	IMB_rect_from_float(tmpbuf);
+	SWAP(char *, tmpbuf->rect, ibuf->rect);
+	IMB_freeImBuf(tmpbuf);
+	
+	
 	curvemapping_premultiply(cumap, 1);
 }
 
diff --git a/source/blender/blenkernel/intern/image.c b/source/blender/blenkernel/intern/image.c
index ff5b5019206..f7edb2bd146 100644
--- a/source/blender/blenkernel/intern/image.c
+++ b/source/blender/blenkernel/intern/image.c
@@ -725,6 +725,17 @@ void BKE_image_print_memlist(void)
 	}
 }
 
+/* frees all ibufs used by any image datablocks */
+void BKE_image_free_image_ibufs(void)
+{
+	Image *ima;
+	
+	for(ima= G.main->image.first; ima; ima= ima->id.next) {
+		image_free_buffers(ima);
+	}
+	
+}
+
 void BKE_image_free_all_textures(void)
 {
 	Tex *tex;
@@ -1898,6 +1909,7 @@ static ImBuf *image_get_ibuf_multilayer(Image *ima, ImageUser *iuser)
 			ibuf->rect_float= rpass->rect;
 			ibuf->flags |= IB_rectfloat;
 			ibuf->channels= rpass->channels;
+			ibuf->profile = IB_PROFILE_LINEAR_RGB;
 
 			image_assign_ibuf(ima, ibuf, iuser?iuser->multi_index:IMA_NO_INDEX, 0);
 		}
diff --git a/source/blender/blenkernel/intern/sequencer.c b/source/blender/blenkernel/intern/sequencer.c
index 771fd6a109b..926f7fde14d 100644
--- a/source/blender/blenkernel/intern/sequencer.c
+++ b/source/blender/blenkernel/intern/sequencer.c
@@ -1694,7 +1694,19 @@ static void input_preprocess(Scene *scene, Sequence *seq, TStripElem *se, int cf
 
 	if(seq->flag & SEQ_MAKE_FLOAT) {
 		if (!se->ibuf->rect_float) {
-			IMB_float_from_rect(se->ibuf);
+			if (scene->r.color_mgt_flag & R_COLOR_MANAGEMENT) {
+				IMB_float_from_rect(se->ibuf);
+			} else {
+				int profile = IB_PROFILE_NONE;
+				
+				/* no color management:
+				 * don't disturb the existing profiles */
+				SWAP(int, se->ibuf->profile, profile);
+
+				IMB_float_from_rect(se->ibuf);
+				
+				SWAP(int, se->ibuf->profile, profile);
+			}
 		}
 		if (se->ibuf->rect) {
 			imb_freerectImBuf(se->ibuf);
diff --git a/source/blender/editors/sculpt_paint/paint_image.c b/source/blender/editors/sculpt_paint/paint_image.c
index 2c80a7095e2..77e90e3c7b1 100644
--- a/source/blender/editors/sculpt_paint/paint_image.c
+++ b/source/blender/editors/sculpt_paint/paint_image.c
@@ -4081,10 +4081,17 @@ static int imapaint_canvas_set(ImagePaintState *s, Image *ima)
 
 		s->clonecanvas= ibuf;
 
+		/* temporarily add float rect for cloning */
 		if(s->canvas->rect_float && !s->clonecanvas->rect_float) {
-			/* temporarily add float rect for cloning */
+			int profile = IB_PROFILE_NONE;
+			
+			/* Don't want to color manage, but don't disturb existing profiles */
+			SWAP(int, s->clonecanvas->profile, profile);
+
 			IMB_float_from_rect(s->clonecanvas);
 			s->clonefreefloat= 1;
+			
+			SWAP(int, s->clonecanvas->profile, profile);
 		}
 		else if(!s->canvas->rect_float && !s->clonecanvas->rect)
 			IMB_rect_from_float(s->clonecanvas);
diff --git a/source/blender/editors/space_image/image_draw.c b/source/blender/editors/space_image/image_draw.c
index 46ec41eda58..ea526b13219 100644
--- a/source/blender/editors/space_image/image_draw.c
+++ b/source/blender/editors/space_image/image_draw.c
@@ -126,7 +126,7 @@ static void image_verify_buffer_float(SpaceImage *sima, Image *ima, ImBuf *ibuf,
 			else {
 				if (color_manage) {
 						if (ima && ima->source == IMA_SRC_VIEWER)
-							ibuf->profile = IB_PROFILE_SRGB;
+							ibuf->profile = IB_PROFILE_LINEAR_RGB;
 				} else {
 					ibuf->profile = IB_PROFILE_NONE;
 				}
diff --git a/source/blender/editors/space_node/drawnode.c b/source/blender/editors/space_node/drawnode.c
index afbe54da961..7f8bf2618a4 100644
--- a/source/blender/editors/space_node/drawnode.c
+++ b/source/blender/editors/space_node/drawnode.c
@@ -1269,7 +1269,7 @@ void draw_nodespace_back_pix(ARegion *ar, SpaceNode *snode, int color_manage)
 			
 			if(!ibuf->rect) {
 				if(color_manage)
-					ibuf->profile= IB_PROFILE_SRGB;
+					ibuf->profile = IB_PROFILE_LINEAR_RGB;
 				else
 					ibuf->profile = IB_PROFILE_NONE;
 				IMB_rect_from_float(ibuf);
diff --git a/source/blender/editors/space_sequencer/sequencer_draw.c b/source/blender/editors/space_sequencer/sequencer_draw.c
index a2525430a10..37bb75a5efd 100644
--- a/source/blender/editors/space_sequencer/sequencer_draw.c
+++ b/source/blender/editors/space_sequencer/sequencer_draw.c
@@ -699,8 +699,14 @@ void draw_image_seq(Scene *scene, ARegion *ar, SpaceSeq *sseq)
 		break;
 	}
 
-	if(ibuf->rect_float && ibuf->rect==NULL)
-		IMB_rect_from_float(ibuf);
+	if(ibuf->rect_float && ibuf->rect==NULL) {
+		if (scene->r.color_mgt_flag & R_COLOR_MANAGEMENT) {
+			ibuf->profile = IB_PROFILE_LINEAR_RGB;
+		} else {
+			ibuf->profile = IB_PROFILE_NONE;
+		}
+		IMB_rect_from_float(ibuf);	
+	}
 	
 	/* needed for gla draw */
 	glaDefine2DArea(&ar->winrct);
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 " \
diff --git a/source/blender/makesrna/intern/rna_scene.c b/source/blender/makesrna/intern/rna_scene.c
index 8830583045b..72a5ac9a552 100644
--- a/source/blender/makesrna/intern/rna_scene.c
+++ b/source/blender/makesrna/intern/rna_scene.c
@@ -96,6 +96,7 @@ EnumPropertyItem snap_element_items[] = {
 
 #include "BKE_context.h"
 #include "BKE_global.h"
+#include "BKE_image.h"
 #include "BKE_main.h"
 #include "BKE_node.h"
 #include "BKE_pointcache.h"
@@ -517,6 +518,12 @@ static int rna_SceneRenderData_engine_get(PointerRNA *ptr)
 	return 0;
 }
 
+static void rna_SceneRenderData_color_management_update(Main *bmain, Scene *unused, PointerRNA *ptr)
+{
+	/* reset all generated image block buffers to prevent out-of-date conversions */
+	BKE_image_free_image_ibufs();
+}
+
 static void rna_SceneRenderLayer_name_set(PointerRNA *ptr, const char *value)
 {
 	Scene *scene= (Scene*)ptr->id.data;
@@ -2114,7 +2121,7 @@ static void rna_def_scene_render_data(BlenderRNA *brna)
 	prop= RNA_def_property(srna, "color_management", PROP_BOOLEAN, PROP_NONE);
 	RNA_def_property_boolean_sdna(prop, NULL, "color_mgt_flag", R_COLOR_MANAGEMENT);
 	RNA_def_property_ui_text(prop, "Color Management", "Use color profiles and gamma corrected imaging pipeline");
-	RNA_def_property_update(prop, NC_SCENE|ND_RENDER_OPTIONS|NC_MATERIAL|ND_SHADING, NULL);
+	RNA_def_property_update(prop, NC_SCENE|ND_RENDER_OPTIONS|NC_MATERIAL|ND_SHADING, "rna_SceneRenderData_color_management_update");
 	
 	prop= RNA_def_property(srna, "use_file_extension", PROP_BOOLEAN, PROP_NONE);
 	RNA_def_property_boolean_sdna(prop, NULL, "scemode", R_EXTENSION);
diff --git a/source/blender/nodes/intern/CMP_nodes/CMP_image.c b/source/blender/nodes/intern/CMP_nodes/CMP_image.c
index 89a3072ac8d..a204f8df4b2 100644
--- a/source/blender/nodes/intern/CMP_nodes/CMP_image.c
+++ b/source/blender/nodes/intern/CMP_nodes/CMP_image.c
@@ -64,27 +64,19 @@ static CompBuf *node_composit_get_image(RenderData *rd, Image *ima, ImageUser *i
 	ibuf= BKE_image_get_ibuf(ima, iuser);
 	if(ibuf==NULL)
 		return NULL;
-	
-	if (rd->color_mgt_flag & R_COLOR_MANAGEMENT) {
-		if (ibuf->profile == IB_PROFILE_NONE) {
-			/* if float buffer already exists = already linear */
-			/* else ... */
-			if (ibuf->rect_float == NULL) {
-				imb_freerectfloatImBuf(ibuf);
-				ibuf->profile = IB_PROFILE_SRGB;
-				IMB_float_from_rect(ibuf);
-			} else {
-				ibuf->profile = IB_PROFILE_LINEAR_RGB;
-			}
-		}
-	} else {
-		if (ibuf->profile == IB_PROFILE_SRGB) {
-			if (ibuf->rect_float != NULL) {
-				imb_freerectfloatImBuf(ibuf);
-			}
-			ibuf->profile = IB_PROFILE_NONE;
-			IMB_float_from_rect(ibuf);
+
+	if (!(rd->color_mgt_flag & R_COLOR_MANAGEMENT)) {
+		int profile = IB_PROFILE_NONE;
+		
+		/* temporarily set profile to none to not disturb actual */
+		SWAP(int, ibuf->profile, profile);
+		
+		if (ibuf->rect_float != NULL) {
+			imb_freerectfloatImBuf(ibuf);
 		}
+		IMB_float_from_rect(ibuf);
+		
+		SWAP(int, ibuf->profile, profile);
 	}
 	
 	if (ibuf->rect_float == NULL) {