Code refactoring: add unified image buffer functions for doing float => byte,

byte => float, float => float, byte => byte conversions with profile, dither
and predivide. Previously code for this was spread out too much.

There should be no functional changes, this is so the predivide/table/dither
patches can work correctly.

13 files changed, 650 insertions, 505 deletions

diff --git a/source/blender/blenkernel/BKE_colortools.h b/source/blender/blenkernel/BKE_colortools.h
index fd3a3fea2bb..b358209a0f4 100644
--- a/source/blender/blenkernel/BKE_colortools.h
+++ b/source/blender/blenkernel/BKE_colortools.h
@@ -45,9 +45,6 @@ struct rctf;
 #   define DO_INLINE static inline
 #endif
 
-void				floatbuf_to_srgb_byte(float *rectf, unsigned char *rectc, int x1, int x2, int y1, int y2, int w);
-void				floatbuf_to_byte(float *rectf, unsigned char *rectc, int x1, int x2, int y1, int y2, int w);
-
 struct CurveMapping	*curvemapping_add(int tot, float minx, float miny, float maxx, float maxy);
 void				curvemapping_free(struct CurveMapping *cumap);
 struct CurveMapping	*curvemapping_copy(struct CurveMapping *cumap);
diff --git a/source/blender/blenkernel/intern/colortools.c b/source/blender/blenkernel/intern/colortools.c
index 2f568aa01eb..67bd6a22348 100644
--- a/source/blender/blenkernel/intern/colortools.c
+++ b/source/blender/blenkernel/intern/colortools.c
@@ -52,45 +52,6 @@
 #include "IMB_imbuf.h"
 #include "IMB_imbuf_types.h"
 
-
-void floatbuf_to_srgb_byte(float *rectf, unsigned char *rectc, int x1, int x2, int y1, int y2, int UNUSED(w))
-{
-	int x, y;
-	float *rf= rectf;
-	float srgb[3];
-	unsigned char *rc= rectc;
-	
-	for(y=y1; y<y2; y++) {
-		for(x=x1; x<x2; x++, rf+=4, rc+=4) {
-			srgb[0]= linearrgb_to_srgb(rf[0]);
-			srgb[1]= linearrgb_to_srgb(rf[1]);
-			srgb[2]= linearrgb_to_srgb(rf[2]);
-
-			rc[0]= FTOCHAR(srgb[0]);
-			rc[1]= FTOCHAR(srgb[1]);
-			rc[2]= FTOCHAR(srgb[2]);
-			rc[3]= FTOCHAR(rf[3]);
-		}
-	}
-}
-
-void floatbuf_to_byte(float *rectf, unsigned char *rectc, int x1, int x2, int y1, int y2, int UNUSED(w))
-{
-	int x, y;
-	float *rf= rectf;
-	unsigned char *rc= rectc;
-	
-	for(y=y1; y<y2; y++) {
-		for(x=x1; x<x2; x++, rf+=4, rc+=4) {
-			rc[0]= FTOCHAR(rf[0]);
-			rc[1]= FTOCHAR(rf[1]);
-			rc[2]= FTOCHAR(rf[2]);
-			rc[3]= FTOCHAR(rf[3]);
-		}
-	}
-}
-
-
 /* ********************************* color curve ********************* */
 
 /* ***************** operations on full struct ************* */
diff --git a/source/blender/blenlib/BLI_math_color.h b/source/blender/blenlib/BLI_math_color.h
index 0e33ee2be3f..7fbb4680b6d 100644
--- a/source/blender/blenlib/BLI_math_color.h
+++ b/source/blender/blenlib/BLI_math_color.h
@@ -34,6 +34,8 @@
 extern "C" {
 #endif
 
+#include "BLI_math_inline.h"
+
 /* primaries */
 #define BLI_XYZ_SMPTE	0
 #define BLI_XYZ_REC709_SRGB	1
@@ -48,7 +50,7 @@ extern "C" {
 #define BLI_YCC_ITU_BT601	0
 #define BLI_YCC_ITU_BT709	1
 #define BLI_YCC_JFIF_0_255	2
-	
+
 /******************* Conversion to RGB ********************/
 
 void hsv_to_rgb(float h, float s, float v, float *r, float *g, float *b);
@@ -70,22 +72,23 @@ unsigned int hsv_to_cpack(float h, float s, float v);
 float rgb_to_grayscale(float rgb[3]);
 unsigned char rgb_to_grayscale_byte(unsigned char rgb[3]);
 
-/***************** Profile Transformations ********************/
+/**************** Profile Transformations *****************/
 
 void gamma_correct(float *c, float gamma);
 float rec709_to_linearrgb(float c);
 float linearrgb_to_rec709(float c);
 float srgb_to_linearrgb(float c);
 float linearrgb_to_srgb(float c);
-void srgb_to_linearrgb_v3_v3(float *col_to, float *col_from);
-void linearrgb_to_srgb_v3_v3(float *col_to, float *col_from);
-
-/* rgba buffer convenience functions */
-void srgb_to_linearrgb_rgba_buf(float *col, int tot);
-void linearrgb_to_srgb_rgba_buf(float *col, int tot);
-void srgb_to_linearrgb_rgba_rgba_buf(float *col_to, float *col_from, int tot);
-void linearrgb_to_srgb_rgba_rgba_buf(float *col_to, float *col_from, int tot);
-	
+
+MINLINE void srgb_to_linearrgb_v3_v3(float linear[3], const float srgb[3]);
+MINLINE void linearrgb_to_srgb_v3_v3(float srgb[3], const float linear[3]);
+
+MINLINE void srgb_to_linearrgb_v4(float linear[4], const float srgb[4]);
+MINLINE void linearrgb_to_srgb_v4(float srgb[4], const float linear[4]);
+
+MINLINE void srgb_to_linearrgb_predivide_v4(float linear[4], const float srgb[4]);
+MINLINE void linearrgb_to_srgb_predivide_v4(float srgb[4], const float linear[4]);
+
 /************************** Other *************************/
 
 int constrain_rgb(float *r, float *g, float *b);
@@ -101,6 +104,10 @@ void lift_gamma_gain_to_asc_cdl(float *lift, float *gamma, float *gain, float *o
 void rgb_byte_to_float(const unsigned char *in, float *out);
 void rgb_float_to_byte(const float *in, unsigned char *out);
 
+#ifdef BLI_MATH_INLINE_H
+#include "intern/math_color_inline.c"
+#endif
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/blender/blenlib/intern/math_color.c b/source/blender/blenlib/intern/math_color.c
index 2ef29c1ce94..8f5366b6317 100644
--- a/source/blender/blenlib/intern/math_color.c
+++ b/source/blender/blenlib/intern/math_color.c
@@ -393,57 +393,6 @@ float linearrgb_to_srgb(float c)
 		return  1.055f * powf(c, 1.0f/2.4f) - 0.055f;
 }
 
-void srgb_to_linearrgb_v3_v3(float *col_to, float *col_from)
-{
-	col_to[0] = srgb_to_linearrgb(col_from[0]);
-	col_to[1] = srgb_to_linearrgb(col_from[1]);
-	col_to[2] = srgb_to_linearrgb(col_from[2]);
-}
-
-void linearrgb_to_srgb_v3_v3(float *col_to, float *col_from)
-{
-	col_to[0] = linearrgb_to_srgb(col_from[0]);
-	col_to[1] = linearrgb_to_srgb(col_from[1]);
-	col_to[2] = linearrgb_to_srgb(col_from[2]);
-}
-
-/* todo, should these be moved elsewhere?, they dont belong in imbuf */
-void srgb_to_linearrgb_rgba_buf(float *col, int tot)
-{
-	while(tot--) {
-		srgb_to_linearrgb_v3_v3(col, col);
-		col += 4;
-	}
-}
-
-void linearrgb_to_srgb_rgba_buf(float *col, int tot)
-{
-	while(tot--) {
-		linearrgb_to_srgb_v3_v3(col, col);
-		col += 4;
-	}
-}
-
-void srgb_to_linearrgb_rgba_rgba_buf(float *col_to, float *col_from, int tot)
-{
-	while(tot--) {
-		srgb_to_linearrgb_v3_v3(col_to, col_from);
-		col_to[3]= col_from[3];
-		col_to += 4;
-		col_from += 4;
-	}
-}
-
-void linearrgb_to_srgb_rgba_rgba_buf(float *col_to, float *col_from, int tot)
-{
-	while(tot--) {
-		linearrgb_to_srgb_v3_v3(col_to, col_from);
-		col_to[3]= col_from[3];
-		col_to += 4;
-		col_from += 4;
-	}
-}
-
 void minmax_rgb(short c[])
 {
 	if(c[0]>255) c[0]=255;
diff --git a/source/blender/blenlib/intern/math_color_inline.c b/source/blender/blenlib/intern/math_color_inline.c
new file mode 100644
index 00000000000..aaaa065f14d
--- /dev/null
+++ b/source/blender/blenlib/intern/math_color_inline.c
@@ -0,0 +1,109 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
+ * All rights reserved.
+ *
+ * The Original Code is: some of this file.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ * */
+
+/** \file blender/blenlib/intern/math_color_inline.c
+ *  \ingroup bli
+ */
+
+
+#include "BLI_math_color.h"
+#include "BLI_utildefines.h"
+
+#ifndef BLI_MATH_COLOR_INLINE_H
+#define BLI_MATH_COLOR_INLINE_H
+
+/******************************** Color Space ********************************/
+
+MINLINE void srgb_to_linearrgb_v3_v3(float linear[3], const float srgb[3])
+{
+	linear[0] = srgb_to_linearrgb(srgb[0]);
+	linear[1] = srgb_to_linearrgb(srgb[1]);
+	linear[2] = srgb_to_linearrgb(srgb[2]);
+}
+
+MINLINE void linearrgb_to_srgb_v3_v3(float srgb[3], const float linear[3])
+{
+	srgb[0] = linearrgb_to_srgb(linear[0]);
+	srgb[1] = linearrgb_to_srgb(linear[1]);
+	srgb[2] = linearrgb_to_srgb(linear[2]);
+}
+
+MINLINE void srgb_to_linearrgb_v4(float linear[4], const float srgb[4])
+{
+	srgb_to_linearrgb_v3_v3(linear, srgb);
+	linear[3] = srgb[3];
+}
+
+MINLINE void linearrgb_to_srgb_v4(float srgb[4], const float linear[4])
+{
+	linearrgb_to_srgb_v3_v3(srgb, linear);
+	srgb[3] = linear[3];
+}
+
+/* predivide versions to work on associated/premultipled alpha. if this should
+   be done or not depends on the background the image will be composited over,
+   ideally you would never do color space conversion on an image with alpha
+   because it is ill defined */
+
+MINLINE void srgb_to_linearrgb_predivide_v4(float linear[4], const float srgb[4])
+{
+	float alpha, inv_alpha;
+
+	if(srgb[3] == 1.0f || srgb[3] == 0.0f) {
+		alpha = 1.0f;
+		inv_alpha = 1.0f;
+	}
+	else {
+		alpha = srgb[3];
+		inv_alpha = 1.0f/alpha;
+	}
+
+	linear[0] = srgb_to_linearrgb(srgb[0] * inv_alpha) * alpha;
+	linear[1] = srgb_to_linearrgb(srgb[1] * inv_alpha) * alpha;
+	linear[2] = srgb_to_linearrgb(srgb[2] * inv_alpha) * alpha;
+	linear[3] = srgb[3];
+}
+
+MINLINE void linearrgb_to_srgb_predivide_v4(float srgb[4], const float linear[4])
+{
+	float alpha, inv_alpha;
+
+	if(linear[3] == 1.0f || linear[3] == 0.0f) {
+		alpha = 1.0f;
+		inv_alpha = 1.0f;
+	}
+	else {
+		alpha = linear[3];
+		inv_alpha = 1.0f/alpha;
+	}
+
+	srgb[0] = linearrgb_to_srgb(linear[0] * inv_alpha) * alpha;
+	srgb[1] = linearrgb_to_srgb(linear[1] * inv_alpha) * alpha;
+	srgb[2] = linearrgb_to_srgb(linear[2] * inv_alpha) * alpha;
+	srgb[3] = linear[3];
+}
+
+#endif /* BLI_MATH_COLOR_INLINE_H */
+
diff --git a/source/blender/editors/render/render_internal.c b/source/blender/editors/render/render_internal.c
index 8a580627da3..bff93fea067 100644
--- a/source/blender/editors/render/render_internal.c
+++ b/source/blender/editors/render/render_internal.c
@@ -76,10 +76,10 @@
 /* called inside thread! */
 void image_buffer_rect_update(Scene *scene, RenderResult *rr, ImBuf *ibuf, volatile rcti *renrect)
 {
-	float x1, y1, *rectf= NULL;
+	float *rectf= NULL;
 	int ymin, ymax, xmin, xmax;
-	int rymin, rxmin, do_color_management;
-	char *rectc;
+	int rymin, rxmin, predivide, profile_from;
+	unsigned char *rectc;
 
 	/* if renrect argument, we only refresh scanlines */
 	if(renrect) {
@@ -136,50 +136,17 @@ void image_buffer_rect_update(Scene *scene, RenderResult *rr, ImBuf *ibuf, volat
 		imb_addrectImBuf(ibuf);
 	
 	rectf+= 4*(rr->rectx*ymin + xmin);
-	rectc= (char *)(ibuf->rect + ibuf->x*rymin + rxmin);
+	rectc= (unsigned char*)(ibuf->rect + ibuf->x*rymin + rxmin);
 
-	do_color_management = (scene && (scene->r.color_mgt_flag & R_COLOR_MANAGEMENT));
-	
-	/* XXX make nice consistent functions for this */
-	for(y1= 0; y1<ymax; y1++) {
-		float *rf= rectf;
-		float srgb[3];
-		char *rc= rectc;
-		const float dither = ibuf->dither / 255.0f;
-
-		/* XXX temp. because crop offset */
-		if(rectc >= (char *)(ibuf->rect)) {
-			for(x1= 0; x1<xmax; x1++, rf += 4, rc+=4) {
-				/* color management */
-				if(do_color_management) {
-					srgb[0]= linearrgb_to_srgb(rf[0]);
-					srgb[1]= linearrgb_to_srgb(rf[1]);
-					srgb[2]= linearrgb_to_srgb(rf[2]);
-				}
-				else {
-					copy_v3_v3(srgb, rf);
-				}
-
-				/* dither */
-				if(dither != 0.0f) {
-					const float d = (BLI_frand()-0.5f)*dither;
-
-					srgb[0] += d;
-					srgb[1] += d;
-					srgb[2] += d;
-				}
-
-				/* write */
-				rc[0]= FTOCHAR(srgb[0]);
-				rc[1]= FTOCHAR(srgb[1]);
-				rc[2]= FTOCHAR(srgb[2]);
-				rc[3]= FTOCHAR(rf[3]);
-			}
-		}
+	if(scene && (scene->r.color_mgt_flag & R_COLOR_MANAGEMENT))
+		profile_from= IB_PROFILE_LINEAR_RGB;
+	else
+		profile_from= IB_PROFILE_SRGB;
+	predivide= 0;
 
-		rectf += 4*rr->rectx;
-		rectc += 4*ibuf->x;
-	}
+	IMB_buffer_byte_from_float(rectc, rectf,
+		4, ibuf->dither, IB_PROFILE_SRGB, profile_from, predivide,
+		xmax, ymax, ibuf->x, rr->rectx);
 }
 
 /* ****************************** render invoking ***************** */
diff --git a/source/blender/editors/render/render_opengl.c b/source/blender/editors/render/render_opengl.c
index 35b21c626ed..be4d54ae2e8 100644
--- a/source/blender/editors/render/render_opengl.c
+++ b/source/blender/editors/render/render_opengl.c
@@ -206,14 +206,11 @@ static void screen_opengl_render_apply(OGLRender *oglrender)
 	 * float buffer. */
 
 	if(oglrender->scene->r.color_mgt_flag & R_COLOR_MANAGEMENT) {
-		float *rctf = rr->rectf;
-		int i;
+		int predivide= 0; /* no alpha */
 
-		for (i = oglrender->sizex * oglrender->sizey; i > 0; i--, rctf+=4) {
-			rctf[0]= srgb_to_linearrgb(rctf[0]);
-			rctf[1]= srgb_to_linearrgb(rctf[1]);
-			rctf[2]= srgb_to_linearrgb(rctf[2]);
-		}
+		IMB_buffer_float_from_float(rr->rectf, rr->rectf,
+			4, IB_PROFILE_LINEAR_RGB, IB_PROFILE_SRGB, predivide,
+			oglrender->sizex, oglrender->sizey, oglrender->sizex, oglrender->sizex);
 	}
 
 	RE_ReleaseResult(oglrender->re);
diff --git a/source/blender/editors/screen/glutil.c b/source/blender/editors/screen/glutil.c
index 0bba9838005..8f04940efd6 100644
--- a/source/blender/editors/screen/glutil.c
+++ b/source/blender/editors/screen/glutil.c
@@ -45,6 +45,9 @@
 #include "BIF_gl.h"
 #include "BIF_glutil.h"
 
+#include "IMB_imbuf.h"
+#include "IMB_imbuf_types.h"
+
 #ifndef GL_CLAMP_TO_EDGE
 #define GL_CLAMP_TO_EDGE                        0x812F
 #endif
@@ -563,17 +566,17 @@ void glaDrawPixelsTex(float x, float y, int img_w, int img_h, int format, void *
 void glaDrawPixelsSafe_to32(float fx, float fy, int img_w, int img_h, int UNUSED(row_w), float *rectf, int do_gamma_correct)
 {
 	unsigned char *rect32;
+	int profile_from= (do_gamma_correct)? IB_PROFILE_LINEAR_RGB: IB_PROFILE_SRGB;
+	int predivide= 0;
 	
 	/* copy imgw-imgh to a temporal 32 bits rect */
 	if(img_w<1 || img_h<1) return;
 	
 	rect32= MEM_mallocN(img_w*img_h*sizeof(int), "temp 32 bits");
 	
-	if (do_gamma_correct) {
-		floatbuf_to_srgb_byte(rectf, rect32, 0, img_w, 0, img_h, img_w);
-	} else {
-		floatbuf_to_byte(rectf, rect32, 0, img_w, 0, img_h, img_w);
-	 }
+	IMB_buffer_byte_from_float(rect32, rectf,
+		4, 0, IB_PROFILE_SRGB, profile_from, predivide, 
+		img_w, img_h, img_w, img_w);
 	
 	glaDrawPixelsSafe(fx, fy, img_w, img_h, img_w, GL_RGBA, GL_UNSIGNED_BYTE, rect32);
 
diff --git a/source/blender/imbuf/IMB_imbuf.h b/source/blender/imbuf/IMB_imbuf.h
index 39282335f46..7f99fc3ffc7 100644
--- a/source/blender/imbuf/IMB_imbuf.h
+++ b/source/blender/imbuf/IMB_imbuf.h
@@ -378,6 +378,20 @@ void IMB_convert_profile(struct ImBuf *ibuf, int profile);
 float *IMB_float_profile_ensure(struct ImBuf *ibuf, int profile, int *alloc);
 void IMB_color_to_bw(struct ImBuf *ibuf);
 
+/* converting pixel buffers */
+void IMB_buffer_byte_from_float(unsigned char *rect_to, const float *rect_from,
+	int channels_from, int dither, int profile_to, int profile_from, int predivide,
+	int width, int height, int stride_to, int stride_from);
+void IMB_buffer_float_from_byte(float *rect_to, const unsigned char *rect_from,
+	int profile_to, int profile_from, int predivide,
+	int width, int height, int stride_to, int stride_from);
+void IMB_buffer_float_from_float(float *rect_to, const float *rect_from,
+	int channels_from, int profile_to, int profile_from, int predivide,
+	int width, int height, int stride_to, int stride_from);
+void IMB_buffer_byte_from_byte(unsigned char *rect_to, const unsigned char *rect_from,
+	int profile_to, int profile_from, int predivide,
+	int width, int height, int stride_to, int stride_from);
+
 /**
  * Change the ordering of the color bytes pointed to by rect from
  * rgba to abgr. size * 4 color bytes are reordered.
diff --git a/source/blender/imbuf/intern/divers.c b/source/blender/imbuf/intern/divers.c
index 8c5f2dcafd6..8a3f6358c5b 100644
--- a/source/blender/imbuf/intern/divers.c
+++ b/source/blender/imbuf/intern/divers.c
@@ -42,10 +42,10 @@
 #include "IMB_imbuf.h"
 #include "IMB_allocimbuf.h"
 
-#include "BKE_colortools.h"
-
 #include "MEM_guardedalloc.h"
 
+/**************************** Interlace/Deinterlace **************************/
+
 void IMB_de_interlace(struct ImBuf *ibuf)
 {
 	struct ImBuf * tbuf1, * tbuf2;
@@ -100,347 +100,498 @@ void IMB_interlace(struct ImBuf *ibuf)
 	}
 }
 
+/************************* Generic Buffer Conversion *************************/
 
-/* assume converting from linear float to sRGB byte */
-void IMB_rect_from_float(struct ImBuf *ibuf)
+MINLINE void byte_to_float_v4(float f[4], const uchar b[4])
 {
-	/* quick method to convert floatbuf to byte */
-	float *tof = (float *)ibuf->rect_float;
-//	int do_dither = ibuf->dither != 0.f;
-	float dither= ibuf->dither / 255.0f;
-	float srgb[4];
-	int i, channels= ibuf->channels;
-	short profile= ibuf->profile;
-	unsigned char *to = (unsigned char *) ibuf->rect;
-	
-	if(tof==NULL) return;
-	if(to==NULL) {
-		imb_addrectImBuf(ibuf);
-		to = (unsigned char *) ibuf->rect;
-	}
-	
-	if(channels==1) {
-		for (i = ibuf->x * ibuf->y; i > 0; i--, to+=4, tof++)
-			to[1]= to[2]= to[3]= to[0] = FTOCHAR(tof[0]);
+	f[0] = b[0] * (1.0f/255.0f);
+	f[1] = b[1] * (1.0f/255.0f);
+	f[2] = b[2] * (1.0f/255.0f);
+	f[3] = b[3] * (1.0f/255.0f);
+}
+
+MINLINE void float_to_byte_v4(uchar b[4], const float f[4])
+{
+	F4TOCHAR4(f, b);
+}
+
+MINLINE void float_to_byte_dither_v4(uchar b[4], const float f[4], float dither)
+{
+	float tmp[4] = {f[0]+dither, f[1]+dither, f[2]+dither, f[3]+dither};
+	float_to_byte_v4(b, tmp);
+}
+
+/* float to byte pixels, output 4-channel RGBA */
+void IMB_buffer_byte_from_float(uchar *rect_to, const float *rect_from,
+	int channels_from, int dither, int profile_to, int profile_from, int predivide,
+	int width, int height, int stride_to, int stride_from)
+{
+	float tmp[4];
+	float dither_fac = dither/255.0f;
+	int x, y;
+
+	/* we need valid profiles */
+	BLI_assert(profile_to != IB_PROFILE_NONE);
+	BLI_assert(profile_from != IB_PROFILE_NONE);
+
+	if(channels_from==1) {
+		/* single channel input */
+		for(y = 0; y < height; y++) {
+			const float *from = rect_from + stride_from*y;
+			uchar *to = rect_to + stride_to*y*4;
+
+			for(x = 0; x < width; x++, from++, to+=4)
+				to[0] = to[1] = to[2] = to[3] = FTOCHAR(from[0]);
+		}
 	}
-	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]);
-				srgb[1]= linearrgb_to_srgb(tof[1]);
-				srgb[2]= linearrgb_to_srgb(tof[2]);
-
-				to[0] = FTOCHAR(srgb[0]);
-				to[1] = FTOCHAR(srgb[1]);
-				to[2] = FTOCHAR(srgb[2]);
-				to[3] = 255;
+	else if(channels_from == 3) {
+		/* RGB input */
+		for(y = 0; y < height; y++) {
+			const float *from = rect_from + stride_from*y*3;
+			uchar *to = rect_to + stride_to*y*4;
+
+			if(profile_to == profile_from) {
+				/* no color space conversion */
+				for(x = 0; x < width; x++, from+=3, to+=4) {
+					F3TOCHAR3(from, to);
+					to[3] = 255;
+				}
+			}
+			else if(profile_to == IB_PROFILE_SRGB) {
+				/* convert from linear to sRGB */
+				for(x = 0; x < width; x++, from+=3, to+=4) {
+					linearrgb_to_srgb_v3_v3(tmp, from);
+					F3TOCHAR3(tmp, to);
+					to[3] = 255;
+				}
+			}
+			else if(profile_to == IB_PROFILE_LINEAR_RGB) {
+				/* convert from sRGB to linear */
+				for(x = 0; x < width; x++, from+=3, to+=4) {
+					srgb_to_linearrgb_v3_v3(tmp, from);
+					F3TOCHAR3(tmp, to);
+					to[3] = 255;
+				}
 			}
 		}
-		else if (channels == 4) {
-			if (dither != 0.f) {
-				for (i = ibuf->x * ibuf->y; i > 0; i--, to+=4, tof+=4) {
-					const float d = (BLI_frand()-0.5f)*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 if(channels_from == 4) {
+		/* RGBA input */
+		for(y = 0; y < height; y++) {
+			const float *from = rect_from + stride_from*y*4;
+			uchar *to = rect_to + stride_to*y*4;
+
+			if(profile_to == profile_from) {
+				/* no color space conversion */
+				if(dither) {
+					for(x = 0; x < width; x++, from+=4, to+=4)
+						float_to_byte_dither_v4(to, from, (BLI_frand()-0.5f)*dither_fac);
+				}
+				else {
+					for(x = 0; x < width; x++, from+=4, to+=4)
+						float_to_byte_v4(to, from);
+				}
+			}
+			else if(profile_to == IB_PROFILE_SRGB) {
+				/* convert from linear to sRGB */
+				if(dither && predivide) {
+					for(x = 0; x < width; x++, from+=4, to+=4) {
+						linearrgb_to_srgb_predivide_v4(tmp, from);
+						float_to_byte_dither_v4(to, tmp, (BLI_frand()-0.5f)*dither_fac);
+					}
+				}
+				else if(dither) {
+					for(x = 0; x < width; x++, from+=4, to+=4) {
+						linearrgb_to_srgb_v4(tmp, from);
+						float_to_byte_dither_v4(to, tmp, (BLI_frand()-0.5f)*dither_fac);
+					}
+				}
+				else if(predivide) {
+					for(x = 0; x < width; x++, from+=4, to+=4) {
+						linearrgb_to_srgb_predivide_v4(tmp, from);
+						float_to_byte_v4(to, tmp);
+					}
+				}
+				else {
+					for(x = 0; x < width; x++, from+=4, to+=4) {
+						linearrgb_to_srgb_v4(tmp, from);
+						float_to_byte_v4(to, tmp);
+					}
+				}
+			}
+			else if(profile_to == IB_PROFILE_LINEAR_RGB) {
+				/* convert from sRGB to linear */
+				if(dither && predivide) {
+					for(x = 0; x < width; x++, from+=4, to+=4) {
+						srgb_to_linearrgb_predivide_v4(tmp, from);
+						float_to_byte_dither_v4(to, tmp, (BLI_frand()-0.5f)*dither_fac);
+					}
+				}
+				else if(dither) {
+					for(x = 0; x < width; x++, from+=4, to+=4) {
+						srgb_to_linearrgb_v4(tmp, from);
+						float_to_byte_dither_v4(to, tmp, (BLI_frand()-0.5f)*dither_fac);
+					}
+				}
+				else if(predivide) {
+					for(x = 0; x < width; x++, from+=4, to+=4) {
+						srgb_to_linearrgb_predivide_v4(tmp, from);
+						float_to_byte_v4(to, tmp);
+					}
+				}
+				else {
+					for(x = 0; x < width; x++, from+=4, to+=4) {
+						srgb_to_linearrgb_v4(tmp, from);
+						float_to_byte_v4(to, tmp);
+					}
 				}
-			} else {
-				floatbuf_to_srgb_byte(tof, to, 0, ibuf->x, 0, ibuf->y, ibuf->x);
 			}
 		}
 	}
-	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]);
-				to[1] = FTOCHAR(tof[1]);
-				to[2] = FTOCHAR(tof[2]);
-				to[3] = 255;
+}
+
+/* byte to float pixels, input and output 4-channel RGBA  */
+void IMB_buffer_float_from_byte(float *rect_to, const uchar *rect_from,
+	int profile_to, int profile_from, int predivide,
+	int width, int height, int stride_to, int stride_from)
+{
+	float tmp[4];
+	int x, y;
+
+	/* we need valid profiles */
+	BLI_assert(profile_to != IB_PROFILE_NONE);
+	BLI_assert(profile_from != IB_PROFILE_NONE);
+
+	/* RGBA input */
+	for(y = 0; y < height; y++) {
+		const uchar *from = rect_from + stride_from*y*4;
+		float *to = rect_to + stride_to*y*4;
+
+		if(profile_to == profile_from) {
+			/* no color space conversion */
+			for(x = 0; x < width; x++, from+=4, to+=4)
+				byte_to_float_v4(to, from);
+		}
+		else if(profile_to == IB_PROFILE_LINEAR_RGB) {
+			/* convert sRGB to linear */
+			if(predivide) {
+				for(x = 0; x < width; x++, from+=4, to+=4) {
+					byte_to_float_v4(tmp, from);
+					srgb_to_linearrgb_predivide_v4(to, tmp);
+				}
+			}
+			else {
+				for(x = 0; x < width; x++, from+=4, to+=4) {
+					byte_to_float_v4(tmp, from);
+					srgb_to_linearrgb_v4(to, tmp);
+				}
 			}
 		}
-		else {
-			if (dither != 0.f) {
-				for (i = ibuf->x * ibuf->y; i > 0; i--, to+=4, tof+=4) {
-					const float d = (BLI_frand()-0.5f)*dither;
-					float col[4];
-
-					col[0]= d + tof[0];
-					col[1]= d + tof[1];
-					col[2]= d + tof[2];
-					col[3]= d + tof[3];
-
-					to[0] = FTOCHAR(col[0]);
-					to[1] = FTOCHAR(col[1]);
-					to[2] = FTOCHAR(col[2]);
-					to[3] = FTOCHAR(col[3]);
+		else if(profile_to == IB_PROFILE_SRGB) {
+			/* convert linear to sRGB */
+			if(predivide) {
+				for(x = 0; x < width; x++, from+=4, to+=4) {
+					byte_to_float_v4(tmp, from);
+					linearrgb_to_srgb_predivide_v4(to, tmp);
 				}
-			} 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 {
+				for(x = 0; x < width; x++, from+=4, to+=4) {
+					byte_to_float_v4(tmp, from);
+					linearrgb_to_srgb_v4(to, tmp);
 				}
 			}
 		}
 	}
-	/* ensure user flag is reset */
-	ibuf->userflags &= ~IB_RECT_INVALID;
 }
 
- 
-
-/* converts from linear float to sRGB byte for part of the texture, buffer will hold the changed part */
-void IMB_partial_rect_from_float(struct ImBuf *ibuf,float *buffer, int x, int y, int w, int h)
+/* float to float pixels, output 4-channel RGBA */
+void IMB_buffer_float_from_float(float *rect_to, const float *rect_from,
+	int channels_from, int profile_to, int profile_from, int predivide,
+	int width, int height, int stride_to, int stride_from)
 {
-	/* indices to source and destination image pixels */
-	float *srcFloatPxl;
-	unsigned char *dstBytePxl;
-	/* buffer index will fill buffer */
-	float *bufferIndex;
-
-	/* convenience pointers to start of image buffers */
-	float *init_srcFloatPxl = (float *)ibuf->rect_float;
-	unsigned char *init_dstBytePxl = (unsigned char *) ibuf->rect;
-
-	/* Dithering factor */
-	float dither= ibuf->dither / 255.0f;
-	/* respective attributes of image */
-	short profile= ibuf->profile;
-	int channels= ibuf->channels;
-	
-	int i, j;
-	
-	/*
-		if called -only- from GPU_paint_update_image this test will never fail
-		but leaving it here for better or worse
-	*/
-	if(init_srcFloatPxl==NULL || (buffer == NULL)){
-		return;
-	}
-	if(init_dstBytePxl==NULL) {
-		imb_addrectImBuf(ibuf);
-		init_dstBytePxl = (unsigned char *) ibuf->rect;
+	int x, y;
+
+	/* we need valid profiles */
+	BLI_assert(profile_to != IB_PROFILE_NONE);
+	BLI_assert(profile_from != IB_PROFILE_NONE);
+
+	if(channels_from==1) {
+		/* single channel input */
+		for(y = 0; y < height; y++) {
+			const float *from = rect_from + stride_from*y;
+			float *to = rect_to + stride_to*y*4;
+
+			for(x = 0; x < width; x++, from++, to+=4)
+				to[0] = to[1] = to[2] = to[3] = from[0];
+		}
 	}
-	if(channels==1) {
-			for (j = 0; j < h; j++){
-				bufferIndex = buffer + w*j*4;
-				dstBytePxl = init_dstBytePxl + (ibuf->x*(y + j) + x)*4;
-				srcFloatPxl = init_srcFloatPxl + (ibuf->x*(y + j) + x);
-				for(i = 0;  i < w; i++, dstBytePxl+=4, srcFloatPxl++, bufferIndex+=4) {
-					dstBytePxl[1]= dstBytePxl[2]= dstBytePxl[3]= dstBytePxl[0] = FTOCHAR(srcFloatPxl[0]);
-					bufferIndex[0] = bufferIndex[1] = bufferIndex[2] = bufferIndex[3] = srcFloatPxl[0];
+	else if(channels_from == 3) {
+		/* RGB input */
+		for(y = 0; y < height; y++) {
+			const float *from = rect_from + stride_from*y*3;
+			float *to = rect_to + stride_to*y*4;
+
+			if(profile_to == profile_from) {
+				/* no color space conversion */
+				for(x = 0; x < width; x++, from+=3, to+=4) {
+					copy_v3_v3(to, from);
+					to[3] = 1.0f;
 				}
 			}
-	}
-	else if (profile == IB_PROFILE_LINEAR_RGB) {
-		if(channels == 3) {
-			for (j = 0; j < h; j++){
-				bufferIndex = buffer + w*j*4;
-				dstBytePxl = init_dstBytePxl + (ibuf->x*(y + j) + x)*4;
-				srcFloatPxl = init_srcFloatPxl + (ibuf->x*(y + j) + x)*3;
-				for(i = 0;  i < w; i++, dstBytePxl+=4, srcFloatPxl+=3, bufferIndex += 4) {
-					linearrgb_to_srgb_v3_v3(bufferIndex, srcFloatPxl);
-					F3TOCHAR4(bufferIndex, dstBytePxl);
-					bufferIndex[3]= 1.0;
+			else if(profile_to == IB_PROFILE_LINEAR_RGB) {
+				/* convert from sRGB to linear */
+				for(x = 0; x < width; x++, from+=3, to+=4) {
+					srgb_to_linearrgb_v3_v3(to, from);
+					to[3] = 1.0f;
+				}
+			}
+			else if(profile_to == IB_PROFILE_SRGB) {
+				/* convert from linear to sRGB */
+				for(x = 0; x < width; x++, from+=3, to+=4) {
+					linearrgb_to_srgb_v3_v3(to, from);
+					to[3] = 1.0f;
 				}
 			}
 		}
-		else if (channels == 4) {
-			if (dither != 0.f) {
-				for (j = 0; j < h; j++){
-					bufferIndex = buffer + w*j*4;
-					dstBytePxl = init_dstBytePxl + (ibuf->x*(y + j) + x)*4;
-					srcFloatPxl = init_srcFloatPxl + (ibuf->x*(y + j) + x)*4;
-					for(i = 0;  i < w; i++, dstBytePxl+=4, srcFloatPxl+=4, bufferIndex+=4) {
-						const float d = (BLI_frand()-0.5f)*dither;
-						linearrgb_to_srgb_v3_v3(bufferIndex, srcFloatPxl);
-						bufferIndex[3] = srcFloatPxl[3];
-						add_v4_fl(bufferIndex, d);
-						F4TOCHAR4(bufferIndex, dstBytePxl);
-					}
+	}
+	else if(channels_from == 4) {
+		/* RGBA input */
+		for(y = 0; y < height; y++) {
+			const float *from = rect_from + stride_from*y*4;
+			float *to = rect_to + stride_to*y*4;
+
+			if(profile_to == profile_from) {
+				/* same profile, copy */
+				memcpy(to, from, sizeof(float)*4*width);
+			}
+			else if(profile_to == IB_PROFILE_LINEAR_RGB) {
+				/* convert to sRGB to linear */
+				if(predivide) {
+					for(x = 0; x < width; x++, from+=4, to+=4)
+						srgb_to_linearrgb_predivide_v4(to, from);
 				}
-			} else {
-				for (j = 0; j < h; j++){
-					bufferIndex = buffer + w*j*4;
-					dstBytePxl = init_dstBytePxl + (ibuf->x*(y + j) + x)*4;
-					srcFloatPxl = init_srcFloatPxl + (ibuf->x*(y + j) + x)*4;
-					for(i = 0;  i < w; i++, dstBytePxl+=4, srcFloatPxl+=4, bufferIndex+=4) {
-						linearrgb_to_srgb_v3_v3(bufferIndex, srcFloatPxl);
-						bufferIndex[3]= srcFloatPxl[3];
-						F4TOCHAR4(bufferIndex, dstBytePxl);
-					}
+				else {
+					for(x = 0; x < width; x++, from+=4, to+=4)
+						srgb_to_linearrgb_v4(to, from);
+				}
+			}
+			else if(profile_to == IB_PROFILE_SRGB) {
+				/* convert from linear to sRGB */
+				if(predivide) {
+					for(x = 0; x < width; x++, from+=4, to+=4)
+						linearrgb_to_srgb_predivide_v4(to, from);
+				}
+				else {
+					for(x = 0; x < width; x++, from+=4, to+=4)
+						linearrgb_to_srgb_v4(to, from);
 				}
 			}
 		}
 	}
-	else if(ELEM(profile, IB_PROFILE_NONE, IB_PROFILE_SRGB)) {
-		if(channels==3) {
-			for (j = 0; j < h; j++){
-				bufferIndex = buffer + w*j*4;
-				dstBytePxl = init_dstBytePxl + (ibuf->x*(y + j) + x)*4;
-				srcFloatPxl = init_srcFloatPxl + (ibuf->x*(y + j) + x)*3;
-				for(i = 0;  i < w; i++, dstBytePxl+=4, srcFloatPxl+=3, bufferIndex+=4) {
-					copy_v3_v3(bufferIndex, srcFloatPxl);
-					F3TOCHAR4(bufferIndex, dstBytePxl);
-					bufferIndex[3] = 1.0;
+}
+
+/* byte to byte pixels, input and output 4-channel RGBA */
+void IMB_buffer_byte_from_byte(uchar *rect_to, const uchar *rect_from,
+	int profile_to, int profile_from, int predivide,
+	int width, int height, int stride_to, int stride_from)
+{
+	float tmp[4];
+	int x, y;
+
+	/* we need valid profiles */
+	BLI_assert(profile_to != IB_PROFILE_NONE);
+	BLI_assert(profile_from != IB_PROFILE_NONE);
+
+	/* always RGBA input */
+	for(y = 0; y < height; y++) {
+		const uchar *from = rect_from + stride_from*y*4;
+		uchar *to = rect_to + stride_to*y*4;
+
+		if(profile_to == profile_from) {
+			/* same profile, copy */
+			memcpy(to, from, sizeof(uchar)*4*width);
+		}
+		else if(profile_to == IB_PROFILE_LINEAR_RGB) {
+			/* convert to sRGB to linear */
+			if(predivide) {
+				for(x = 0; x < width; x++, from+=4, to+=4) {
+					byte_to_float_v4(tmp, from);
+					srgb_to_linearrgb_predivide_v4(tmp, tmp);
+					float_to_byte_v4(to, tmp);
+				}
+			}
+			else {
+				for(x = 0; x < width; x++, from+=4, to+=4) {
+					byte_to_float_v4(tmp, from);
+					srgb_to_linearrgb_v4(tmp, tmp);
+					float_to_byte_v4(to, tmp);
 				}
 			}
 		}
-		else {
-			if (dither != 0.f) {
-				for (j = 0; j < h; j++){
-					bufferIndex = buffer + w*j*4;
-					dstBytePxl = init_dstBytePxl + (ibuf->x*(y + j) + x)*4;
-					srcFloatPxl = init_srcFloatPxl + (ibuf->x*(y + j) + x)*4;
-					for(i = 0;  i < w; i++, dstBytePxl+=4, srcFloatPxl+=4, bufferIndex+=4) {
-						const float d = (BLI_frand()-0.5f)*dither;
-						copy_v4_v4(bufferIndex, srcFloatPxl);
-						add_v4_fl(bufferIndex,d);
-						F4TOCHAR4(bufferIndex, dstBytePxl);
-					}
+		else if(profile_to == IB_PROFILE_SRGB) {
+			/* convert from linear to sRGB */
+			if(predivide) {
+				for(x = 0; x < width; x++, from+=4, to+=4) {
+					byte_to_float_v4(tmp, from);
+					linearrgb_to_srgb_predivide_v4(tmp, tmp);
+					float_to_byte_v4(to, tmp);
 				}
-			} else {
-				for (j = 0; j < h; j++){
-					bufferIndex = buffer + w*j*4;
-					dstBytePxl = init_dstBytePxl + (ibuf->x*(y + j) + x)*4;
-					srcFloatPxl = init_srcFloatPxl + (ibuf->x*(y + j) + x)*4;
-					for(i = 0;  i < w; i++, dstBytePxl+=4, srcFloatPxl+=4, bufferIndex+=4) {
-						copy_v4_v4(bufferIndex, srcFloatPxl);
-						F4TOCHAR4(bufferIndex, dstBytePxl);
-					}
+			}
+			else {
+				for(x = 0; x < width; x++, from+=4, to+=4) {
+					byte_to_float_v4(tmp, from);
+					linearrgb_to_srgb_v4(tmp, tmp);
+					float_to_byte_v4(to, tmp);
 				}
 			}
 		}
 	}
+}
+
+/****************************** ImBuf Conversion *****************************/
+
+void IMB_rect_from_float(struct ImBuf *ibuf)
+{
+	int predivide= 0, profile_from;
+
+	/* verify we have a float buffer */
+	if(ibuf->rect_float==NULL)
+		return;
+
+	/* create byte rect if it didn't exist yet */
+	if(ibuf->rect==NULL)
+		imb_addrectImBuf(ibuf);
+
+	/* determine profiles */
+	if(ibuf->profile == IB_PROFILE_LINEAR_RGB)
+		profile_from = IB_PROFILE_LINEAR_RGB;
+	else if(ELEM(ibuf->profile, IB_PROFILE_SRGB, IB_PROFILE_NONE))
+		profile_from = IB_PROFILE_SRGB;
+	else
+		BLI_assert(0);
+
+	/* do conversion */
+	IMB_buffer_byte_from_float((uchar*)ibuf->rect, ibuf->rect_float,
+		ibuf->channels, ibuf->dither, IB_PROFILE_SRGB, profile_from, predivide,
+		ibuf->x, ibuf->y, ibuf->x, ibuf->x);
+
 	/* ensure user flag is reset */
 	ibuf->userflags &= ~IB_RECT_INVALID;
 }
 
-static void imb_float_from_rect_nonlinear(struct ImBuf *ibuf, float *fbuf)
+/* converts from linear float to sRGB byte for part of the texture, buffer will hold the changed part */
+void IMB_partial_rect_from_float(struct ImBuf *ibuf, float *buffer, int x, int y, int w, int h)
 {
-	float *tof = fbuf;
-	int i;
-	unsigned char *to = (unsigned char *) ibuf->rect;
-
-	for (i = ibuf->x * ibuf->y; i > 0; i--) 
-	{
-		tof[0] = ((float)to[0])*(1.0f/255.0f);
-		tof[1] = ((float)to[1])*(1.0f/255.0f);
-		tof[2] = ((float)to[2])*(1.0f/255.0f);
-		tof[3] = ((float)to[3])*(1.0f/255.0f);
-		to += 4; 
-		tof += 4;
-	}
-}
+	float *rect_float;
+	uchar *rect_byte;
+	int predivide= 0, profile_from;
+
+	/* verify we have a float buffer */
+	if(ibuf->rect_float==NULL || buffer==NULL)
+		return;
 
+	/* create byte rect if it didn't exist yet */
+	if(ibuf->rect==NULL)
+		imb_addrectImBuf(ibuf);
 
-static void imb_float_from_rect_linear(struct ImBuf *ibuf, float *fbuf)
-{
-	float *tof = fbuf;
-	int i;
-	unsigned char *to = (unsigned char *) ibuf->rect;
-
-	for (i = ibuf->x * ibuf->y; i > 0; i--) 
-	{
-		tof[0] = srgb_to_linearrgb(((float)to[0])*(1.0f/255.0f));
-		tof[1] = srgb_to_linearrgb(((float)to[1])*(1.0f/255.0f));
-		tof[2] = srgb_to_linearrgb(((float)to[2])*(1.0f/255.0f));
-		tof[3] = ((float)to[3])*(1.0f/255.0f);
-		to += 4; 
-		tof += 4;
-	}
+	/* determine profiles */
+	if(ibuf->profile == IB_PROFILE_LINEAR_RGB)
+		profile_from = IB_PROFILE_LINEAR_RGB;
+	else if(ELEM(ibuf->profile, IB_PROFILE_SRGB, IB_PROFILE_NONE))
+		profile_from = IB_PROFILE_SRGB;
+	else
+		BLI_assert(0);
+
+	/* do conversion */
+	rect_float= ibuf->rect_float + (x + y*ibuf->x)*ibuf->channels;
+	rect_byte= (uchar*)ibuf->rect + (x + y*ibuf->x)*4;
+
+	IMB_buffer_float_from_float(buffer, rect_float,
+		ibuf->channels, IB_PROFILE_SRGB, profile_from, predivide,
+		w, h, w, ibuf->x);
+
+	IMB_buffer_byte_from_float(rect_byte, buffer,
+		4, ibuf->dither, IB_PROFILE_SRGB, IB_PROFILE_SRGB, 0,
+		w, h, ibuf->x, w);
+
+	/* ensure user flag is reset */
+	ibuf->userflags &= ~IB_RECT_INVALID;
 }
 
 void IMB_float_from_rect(struct ImBuf *ibuf)
 {
-	/* quick method to convert byte to floatbuf */
-	if(ibuf->rect==NULL) return;
-	if(ibuf->rect_float==NULL) {
-		if (imb_addrectfloatImBuf(ibuf) == 0) return;
-	}
+	int predivide= 0, profile_from;
+
+	/* verify if we byte and float buffers */
+	if(ibuf->rect==NULL)
+		return;
+
+	if(ibuf->rect_float==NULL)
+		if(imb_addrectfloatImBuf(ibuf) == 0)
+			return;
 	
-	/* 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 */
-		imb_float_from_rect_linear(ibuf, ibuf->rect_float);
-	} else {
-		imb_float_from_rect_nonlinear(ibuf, ibuf->rect_float);
-	}
+	/* determine profiles */
+	if(ibuf->profile == IB_PROFILE_NONE)
+		profile_from = IB_PROFILE_LINEAR_RGB;
+	else
+		profile_from = IB_PROFILE_SRGB;
+	
+	/* do conversion */
+	IMB_buffer_float_from_byte(ibuf->rect_float, (uchar*)ibuf->rect,
+		IB_PROFILE_LINEAR_RGB, profile_from, predivide,
+		ibuf->x, ibuf->y, ibuf->x, ibuf->x);
 }
 
 /* no profile conversion */
 void IMB_float_from_rect_simple(struct ImBuf *ibuf)
 {
+	int predivide= 0;
+
 	if(ibuf->rect_float==NULL)
 		imb_addrectfloatImBuf(ibuf);
-	imb_float_from_rect_nonlinear(ibuf, ibuf->rect_float);
+
+	IMB_buffer_float_from_byte(ibuf->rect_float, (uchar*)ibuf->rect,
+		IB_PROFILE_SRGB, IB_PROFILE_SRGB, predivide,
+		ibuf->x, ibuf->y, ibuf->x, ibuf->x);
 }
 
 void IMB_convert_profile(struct ImBuf *ibuf, int profile)
 {
-	int ok= FALSE;
-	int i;
-
-	unsigned char *rct= (unsigned char *)ibuf->rect;
-	float *rctf= ibuf->rect_float;
+	int predivide= 0, profile_from, profile_to;
 
 	if(ibuf->profile == profile)
 		return;
 
-	if(ELEM(ibuf->profile, IB_PROFILE_NONE, IB_PROFILE_SRGB)) { /* from */
-		if(profile == IB_PROFILE_LINEAR_RGB) { /* to */
-			if(ibuf->rect_float) {
-				for (i = ibuf->x * ibuf->y; i > 0; i--, rctf+=4) {
-					rctf[0]= srgb_to_linearrgb(rctf[0]);
-					rctf[1]= srgb_to_linearrgb(rctf[1]);
-					rctf[2]= srgb_to_linearrgb(rctf[2]);
-				}
-			}
-			if(ibuf->rect) {
-				for (i = ibuf->x * ibuf->y; i > 0; i--, rct+=4) {
-					rct[0]= (unsigned char)((srgb_to_linearrgb((float)rct[0]/255.0f) * 255.0f) + 0.5f);
-					rct[1]= (unsigned char)((srgb_to_linearrgb((float)rct[1]/255.0f) * 255.0f) + 0.5f);
-					rct[2]= (unsigned char)((srgb_to_linearrgb((float)rct[2]/255.0f) * 255.0f) + 0.5f);
-				}
-			}
-			ok= TRUE;
-		}
-	}
-	else if (ibuf->profile == IB_PROFILE_LINEAR_RGB) { /* from */
-		if(ELEM(profile, IB_PROFILE_NONE, IB_PROFILE_SRGB)) { /* to */
-			if(ibuf->rect_float) {
-				for (i = ibuf->x * ibuf->y; i > 0; i--, rctf+=4) {
-					rctf[0]= linearrgb_to_srgb(rctf[0]);
-					rctf[1]= linearrgb_to_srgb(rctf[1]);
-					rctf[2]= linearrgb_to_srgb(rctf[2]);
-				}
-			}
-			if(ibuf->rect) {
-				for (i = ibuf->x * ibuf->y; i > 0; i--, rct+=4) {
-					rct[0]= (unsigned char)((linearrgb_to_srgb((float)rct[0]/255.0f) * 255.0f) + 0.5f);
-					rct[1]= (unsigned char)((linearrgb_to_srgb((float)rct[1]/255.0f) * 255.0f) + 0.5f);
-					rct[2]= (unsigned char)((linearrgb_to_srgb((float)rct[2]/255.0f) * 255.0f) + 0.5f);
-				}
-			}
-			ok= TRUE;
-		}
+	/* determine profiles */
+	if(ibuf->profile == IB_PROFILE_LINEAR_RGB)
+		profile_from = IB_PROFILE_LINEAR_RGB;
+	else if(ELEM(ibuf->profile, IB_PROFILE_SRGB, IB_PROFILE_NONE))
+		profile_from = IB_PROFILE_SRGB;
+	else
+		BLI_assert(0);
+
+	if(profile == IB_PROFILE_LINEAR_RGB)
+		profile_to = IB_PROFILE_LINEAR_RGB;
+	else if(ELEM(profile, IB_PROFILE_SRGB, IB_PROFILE_NONE))
+		profile_to = IB_PROFILE_SRGB;
+	else
+		BLI_assert(0);
+	
+	/* do conversion */
+	if(ibuf->rect_float) {
+		IMB_buffer_float_from_float(ibuf->rect_float, ibuf->rect_float,
+			4, profile_to, profile_from, predivide,
+			ibuf->x, ibuf->y, ibuf->x, ibuf->x);
 	}
 
-	if(ok==FALSE){
-		printf("IMB_convert_profile: failed profile conversion %d -> %d\n", ibuf->profile, profile);
-		return;
+	if(ibuf->rect) {
+		IMB_buffer_byte_from_byte((uchar*)ibuf->rect, (uchar*)ibuf->rect,
+			profile_to, profile_from, predivide,
+			ibuf->x, ibuf->y, ibuf->x, ibuf->x);
 	}
 
+	/* set new profile */
 	ibuf->profile= profile;
 }
 
@@ -448,18 +599,25 @@ void IMB_convert_profile(struct ImBuf *ibuf, int profile)
  * if the return  */
 float *IMB_float_profile_ensure(struct ImBuf *ibuf, int profile, int *alloc)
 {
-	/* stupid but it works like this everywhere now */
-	const short is_lin_from= (ibuf->profile != IB_PROFILE_NONE);
-	const short is_lin_to= (profile != IB_PROFILE_NONE);
-
+	int predivide= 0, profile_from, profile_to;
+
+	/* determine profiles */
+	if(ibuf->profile == IB_PROFILE_NONE)
+		profile_from = IB_PROFILE_LINEAR_RGB;
+	else
+		profile_from = IB_PROFILE_SRGB;
+
+	if(profile == IB_PROFILE_NONE)
+		profile_to = IB_PROFILE_LINEAR_RGB;
+	else
+		profile_to = IB_PROFILE_SRGB;
 	
-	if(is_lin_from == is_lin_to) {
+	if(profile_from == profile_to) {
+		/* simple case, just allocate the buffer and return */
 		*alloc= 0;
 
-		/* simple case, just allocate the buffer and return */
-		if(ibuf->rect_float == NULL) {
+		if(ibuf->rect_float == NULL)
 			IMB_float_from_rect(ibuf);
-		}
 
 		return ibuf->rect_float;
 	}
@@ -469,42 +627,36 @@ float *IMB_float_profile_ensure(struct ImBuf *ibuf, int profile, int *alloc)
 		*alloc= 1;
 
 		if(ibuf->rect_float == NULL) {
-			if(is_lin_to) {
-				imb_float_from_rect_linear(ibuf, fbuf);
-			}
-			else {
-				imb_float_from_rect_nonlinear(ibuf, fbuf);
-			}
+			IMB_buffer_float_from_byte(fbuf, (uchar*)ibuf->rect,
+				profile_to, profile_from, predivide,
+				ibuf->x, ibuf->y, ibuf->x, ibuf->x);
 		}
 		else {
-			if(is_lin_to) { /* lin -> nonlin */
-				linearrgb_to_srgb_rgba_rgba_buf(fbuf, ibuf->rect_float, ibuf->x * ibuf->y);
-			}
-			else { /* nonlin -> lin */
-				srgb_to_linearrgb_rgba_rgba_buf(fbuf, ibuf->rect_float, ibuf->x * ibuf->y);
-			}
+			IMB_buffer_float_from_float(fbuf, ibuf->rect_float,
+				4, profile_to, profile_from, predivide,
+				ibuf->x, ibuf->y, ibuf->x, ibuf->x);
 		}
 
 		return fbuf;
 	}
 }
 
+/**************************** Color to Grayscale *****************************/
 
 /* no profile conversion */
 void IMB_color_to_bw(struct ImBuf *ibuf)
 {
 	float *rctf= ibuf->rect_float;
-	unsigned char *rct= (unsigned char *)ibuf->rect;
+	uchar *rct= (uchar*)ibuf->rect;
 	int i;
+
 	if(rctf) {
-		for (i = ibuf->x * ibuf->y; i > 0; i--, rctf+=4) {
+		for(i = ibuf->x * ibuf->y; i > 0; i--, rctf+=4)
 			rctf[0]= rctf[1]= rctf[2]= rgb_to_grayscale(rctf);
-		}
 	}
 
 	if(rct) {
-		for (i = ibuf->x * ibuf->y; i > 0; i--, rct+=4) {
+		for(i = ibuf->x * ibuf->y; i > 0; i--, rct+=4)
 			rct[0]= rct[1]= rct[2]= rgb_to_grayscale_byte(rct);
-		}
 	}
 }
diff --git a/source/blender/nodes/composite/node_composite_util.c b/source/blender/nodes/composite/node_composite_util.c
index 99a36691b10..8aaf1771b68 100644
--- a/source/blender/nodes/composite/node_composite_util.c
+++ b/source/blender/nodes/composite/node_composite_util.c
@@ -606,7 +606,9 @@ void generate_preview(void *data, bNode *node, CompBuf *stackbuf)
 	RenderData *rd= data;
 	bNodePreview *preview= node->preview;
 	int xsize, ysize;
-	int color_manage= rd->color_mgt_flag & R_COLOR_MANAGEMENT;
+	int profile_from= (rd->color_mgt_flag & R_COLOR_MANAGEMENT)? IB_PROFILE_LINEAR_RGB: IB_PROFILE_SRGB;
+	int predivide= 0;
+	int dither= 0;
 	unsigned char *rect;
 	
 	if(preview && stackbuf) {
@@ -633,10 +635,9 @@ void generate_preview(void *data, bNode *node, CompBuf *stackbuf)
 		/* convert to byte for preview */
 		rect= MEM_callocN(sizeof(unsigned char)*4*xsize*ysize, "bNodePreview.rect");
 
-		if(color_manage)
-			floatbuf_to_srgb_byte(cbuf->rect, rect, 0, xsize, 0, ysize, xsize);
-		else
-			floatbuf_to_byte(cbuf->rect, rect, 0, xsize, 0, ysize, xsize);
+		IMB_buffer_byte_from_float(rect, cbuf->rect,
+			4, dither, IB_PROFILE_SRGB, profile_from, predivide, 
+			xsize, ysize, xsize, xsize);
 		
 		free_compbuf(cbuf);
 		if(stackbuf_use!=stackbuf)
diff --git a/source/blender/nodes/composite/nodes/node_composite_image.c b/source/blender/nodes/composite/nodes/node_composite_image.c
index 9920cdab039..fd7c87adea2 100644
--- a/source/blender/nodes/composite/nodes/node_composite_image.c
+++ b/source/blender/nodes/composite/nodes/node_composite_image.c
@@ -62,6 +62,7 @@ static bNodeSocketTemplate cmp_node_rlayers_out[]= {
 float *node_composit_get_float_buffer(RenderData *rd, ImBuf *ibuf, int *alloc)
 {
 	float *rect;
+	int predivide= 0;
 
 	*alloc= FALSE;
 
@@ -71,7 +72,11 @@ float *node_composit_get_float_buffer(RenderData *rd, ImBuf *ibuf, int *alloc)
 		}
 		else {
 			rect= MEM_mapallocN(sizeof(float) * 4 * ibuf->x * ibuf->y, "node_composit_get_image");
-			srgb_to_linearrgb_rgba_rgba_buf(rect, ibuf->rect_float, ibuf->x * ibuf->y);
+
+			IMB_buffer_float_from_float(rect, ibuf->rect_float,
+				4, IB_PROFILE_LINEAR_RGB, IB_PROFILE_SRGB, predivide,
+				ibuf->x, ibuf->y, ibuf->x, ibuf->x);
+
 			*alloc= TRUE;
 		}
 	}
@@ -81,7 +86,11 @@ float *node_composit_get_float_buffer(RenderData *rd, ImBuf *ibuf, int *alloc)
 		}
 		else {
 			rect= MEM_mapallocN(sizeof(float) * 4 * ibuf->x * ibuf->y, "node_composit_get_image");
-			linearrgb_to_srgb_rgba_rgba_buf(rect, ibuf->rect_float, ibuf->x * ibuf->y);
+
+			IMB_buffer_float_from_float(rect, ibuf->rect_float,
+				4, IB_PROFILE_SRGB, IB_PROFILE_LINEAR_RGB, predivide,
+				ibuf->x, ibuf->y, ibuf->x, ibuf->x);
+
 			*alloc= TRUE;
 		}
 	}
diff --git a/source/blender/render/intern/source/pipeline.c b/source/blender/render/intern/source/pipeline.c
index d82cff16496..0a481629ee8 100644
--- a/source/blender/render/intern/source/pipeline.c
+++ b/source/blender/render/intern/source/pipeline.c
@@ -1149,32 +1149,17 @@ void RE_ResultGet32(Render *re, unsigned int *rect)
 	
 	RE_AcquireResultImage(re, &rres);
 
-	if(rres.rect32) 
+	if(rres.rect32) {
 		memcpy(rect, rres.rect32, sizeof(int)*rres.rectx*rres.recty);
+	}
 	else if(rres.rectf) {
-		float *fp= rres.rectf;
-		int tot= rres.rectx*rres.recty;
-		char *cp= (char *)rect;
-		
-		if (re->r.color_mgt_flag & R_COLOR_MANAGEMENT) {
-			/* Finally convert back to sRGB rendered image */ 
-			for(;tot>0; tot--, cp+=4, fp+=4) {
-				cp[0] = FTOCHAR(linearrgb_to_srgb(fp[0]));
-				cp[1] = FTOCHAR(linearrgb_to_srgb(fp[1]));
-				cp[2] = FTOCHAR(linearrgb_to_srgb(fp[2]));
-				cp[3] = FTOCHAR(fp[3]);
-			}
-		}
-		else {
-			/* Color management is off : no conversion necessary */
-			for(;tot>0; tot--, cp+=4, fp+=4) {
-				cp[0] = FTOCHAR(fp[0]);
-				cp[1] = FTOCHAR(fp[1]);
-				cp[2] = FTOCHAR(fp[2]);
-				cp[3] = FTOCHAR(fp[3]);
-			}
-		}
+		int profile_from= (re->r.color_mgt_flag & R_COLOR_MANAGEMENT)? IB_PROFILE_LINEAR_RGB: IB_PROFILE_SRGB;
+		int predivide= 0;
+		int dither= 0;
 
+		IMB_buffer_byte_from_float((unsigned char*)rect, rres.rectf,
+			4, dither, IB_PROFILE_SRGB, profile_from, predivide,
+			rres.rectx, rres.recty, rres.rectx, rres.rectx);
 	}
 	else
 		/* else fill with black */
@@ -2567,24 +2552,18 @@ static void do_render_seq(Render * re)
 
 	if(ibuf) {
 		if(ibuf->rect_float) {
+			/* color management: when off ensure rectf is non-lin, since thats what the internal
+			 * render engine delivers */
+			int profile_to= (re->r.color_mgt_flag & R_COLOR_MANAGEMENT)? IB_PROFILE_LINEAR_RGB: IB_PROFILE_SRGB;
+			int profile_from= (ibuf->profile == IB_PROFILE_LINEAR_RGB)? IB_PROFILE_LINEAR_RGB: IB_PROFILE_SRGB;
+			int predivide= 0;
+
 			if (!rr->rectf)
 				rr->rectf= MEM_mallocN(4*sizeof(float)*rr->rectx*rr->recty, "render_seq rectf");
 			
-			/* color management: when off ensure rectf is non-lin, since thats what the internal
-			 * render engine delivers */
-			if(re->r.color_mgt_flag & R_COLOR_MANAGEMENT) {
-				if(ibuf->profile == IB_PROFILE_LINEAR_RGB)
-					memcpy(rr->rectf, ibuf->rect_float, 4*sizeof(float)*rr->rectx*rr->recty);
-				else
-					srgb_to_linearrgb_rgba_rgba_buf(rr->rectf, ibuf->rect_float, rr->rectx*rr->recty);
-					
-			}
-			else {
-				if(ibuf->profile != IB_PROFILE_LINEAR_RGB)
-					memcpy(rr->rectf, ibuf->rect_float, 4*sizeof(float)*rr->rectx*rr->recty);
-				else
-					linearrgb_to_srgb_rgba_rgba_buf(rr->rectf, ibuf->rect_float, rr->rectx*rr->recty);
-			}
+			IMB_buffer_float_from_float(rr->rectf, ibuf->rect_float,
+				4, profile_to, profile_from, predivide,
+				rr->rectx, rr->recty, rr->rectx, rr->rectx);
 			
 			/* TSK! Since sequence render doesn't free the *rr render result, the old rect32
 			   can hang around when sequence render has rendered a 32 bits one before */