source/blender/blenkernel/intern/image_save.cc

@@ -813,7 +813,7 @@ bool BKE_image_render_write_exr(ReportList *reports,
 
       /* We only store RGBA passes as half float, for
        * others precision loss can be problematic. */
-      const bool pass_RGBA = STR_ELEM(rp->chan_id, "RGB", "RGBA", "R", "G", "B", "A");
+      const bool pass_RGBA = RE_RenderPassIsColor(rp);
       const bool pass_half_float = half_float && pass_RGBA;
 
       /* Color-space conversion only happens on RGBA passes. */

source/blender/render/RE_pipeline.h

@@ -502,6 +502,9 @@ RenderResult *RE_DuplicateRenderResult(RenderResult *rr);
 struct ImBuf *RE_RenderPassEnsureImBuf(RenderPass *render_pass);
 struct ImBuf *RE_RenderViewEnsureImBuf(const RenderResult *render_result, RenderView *render_view);
 
+/* Returns true if the pass is a color (as opposite of data) and needs to be color managed. */
+bool RE_RenderPassIsColor(const RenderPass *render_pass);
+
 #ifdef __cplusplus
 }
 #endif

source/blender/render/intern/render_result.cc

@@ -167,6 +167,31 @@ void render_result_views_shallowdelete(RenderResult *rr)
 /** \name New
  * \{ */
 
+static int get_num_planes_for_pass_ibuf(const RenderPass &render_pass)
+{
+  switch (render_pass.channels) {
+    case 1:
+      return R_IMF_PLANES_BW;
+    case 3:
+      return R_IMF_PLANES_RGB;
+    case 4:
+      return R_IMF_PLANES_RGBA;
+  }
+
+  /* Fallback to a commonly used default value of planes for odd-ball number of channel. */
+  return R_IMF_PLANES_RGBA;
+}
+
+static void assign_render_pass_ibuf_colorspace(RenderPass &render_pass)
+{
+  if (RE_RenderPassIsColor(&render_pass)) {
+    return;
+  }
+
+  const char *data_colorspace = IMB_colormanagement_role_colorspace_name_get(COLOR_ROLE_DATA);
+  IMB_colormanagement_assign_float_colorspace(render_pass.ibuf, data_colorspace);
+}
+
 static void render_layer_allocate_pass(RenderResult *rr, RenderPass *rp)
 {
   if (rp->ibuf && rp->ibuf->float_buffer.data) {
@@ -179,9 +204,10 @@ static void render_layer_allocate_pass(RenderResult *rr, RenderPass *rp)
   const size_t rectsize = size_t(rr->rectx) * rr->recty * rp->channels;
   float *buffer_data = MEM_cnew_array<float>(rectsize, rp->name);
 
-  rp->ibuf = IMB_allocImBuf(rr->rectx, rr->recty, 32, 0);
+  rp->ibuf = IMB_allocImBuf(rr->rectx, rr->recty, get_num_planes_for_pass_ibuf(*rp), 0);
   rp->ibuf->channels = rp->channels;
   IMB_assign_float_buffer(rp->ibuf, buffer_data, IB_TAKE_OWNERSHIP);
+  assign_render_pass_ibuf_colorspace(*rp);
 
   if (STREQ(rp->name, RE_PASSNAME_VECTOR)) {
     /* initialize to max speed */
@@ -680,6 +706,7 @@ RenderResult *render_result_new_from_exr(
   RenderResult *rr = MEM_cnew<RenderResult>(__func__);
   const char *to_colorspace = IMB_colormanagement_role_colorspace_name_get(
       COLOR_ROLE_SCENE_LINEAR);
+  const char *data_colorspace = IMB_colormanagement_role_colorspace_name_get(COLOR_ROLE_DATA);
 
   rr->rectx = rectx;
   rr->recty = recty;
@@ -696,7 +723,7 @@ RenderResult *render_result_new_from_exr(
       rpass->rectx = rectx;
       rpass->recty = recty;
 
-      if (rpass->channels >= 3) {
+      if (RE_RenderPassIsColor(rpass)) {
         IMB_colormanagement_transform(rpass->ibuf->float_buffer.data,
                                       rpass->rectx,
                                       rpass->recty,
@@ -705,6 +732,9 @@ RenderResult *render_result_new_from_exr(
                                       to_colorspace,
                                       predivide);
       }
+      else {
+        IMB_colormanagement_assign_float_colorspace(rpass->ibuf, data_colorspace);
+      }
     }
   }
 
@@ -1302,8 +1332,10 @@ RenderResult *RE_DuplicateRenderResult(RenderResult *rr)
 ImBuf *RE_RenderPassEnsureImBuf(RenderPass *render_pass)
 {
   if (!render_pass->ibuf) {
-    render_pass->ibuf = IMB_allocImBuf(render_pass->rectx, render_pass->recty, 32, 0);
+    render_pass->ibuf = IMB_allocImBuf(
+        render_pass->rectx, render_pass->recty, get_num_planes_for_pass_ibuf(*render_pass), 0);
     render_pass->ibuf->channels = render_pass->channels;
+    assign_render_pass_ibuf_colorspace(*render_pass);
   }
 
   return render_pass->ibuf;
@@ -1318,4 +1350,9 @@ ImBuf *RE_RenderViewEnsureImBuf(const RenderResult *render_result, RenderView *r
   return render_view->ibuf;
 }
 
+bool RE_RenderPassIsColor(const RenderPass *render_pass)
+{
+  return STR_ELEM(render_pass->chan_id, "RGB", "RGBA", "R", "G", "B", "A");
+}
+
 /** \} */