Fix a few capture UI irritations

1. As the radius calculating algorithm has been verified for good results for some time now we
   don't need the "validation" any more and trust returned data to be in the 0.0 -> 1.5 range.
2. Fixed a subtle autoradius-once-in-UI flag issue.
3. Instead of avoiding the radius calculation we accept to do so also while being zoomed in or
   with active cropping but leave a control log notice about imprecise results, also modified
   the tooltip for clearer information.
   Also evaluated: if a radius calculation is requested we expand roi_in to full image and calculate
   radius on those data before restarting pipe with current roi.
   There are definitely differences - especially if being zoomed/cropped at image borders - for
   the calculated radius but those are pretty small (mostly <0.05) so it's not worth to do so.

Author: jenshannoschwalm

src/iop/demosaic.c

@@ -1782,8 +1782,8 @@ void gui_init(dt_iop_module_t *self)
                                               "ringing especially when used with a large 'iterations' setting.\n\n"
                                               "Note: a radius set to zero will be recalculated automatically the next run. use for presets"));
   dt_bauhaus_widget_set_quad(g->cs_radius, self, dtgtk_cairo_paint_reset, FALSE, _cs_radius_callback,
-    _("calculate the capture sharpen radius from sensor data.\n"
-      "this should be done in zoomed out darkroom"));
+                                            _("calculate the capture sharpen radius from available raw sensor data.\n"
+                                              "for best results avoid cropping or darkroom zooming in"));
 
   g->cs_thrs = dt_bauhaus_slider_from_params(self, "cs_thrs");
   gtk_widget_set_tooltip_text(g->cs_thrs, _("restrict capture sharpening to areas with high local contrast,\n"

src/iop/demosaicing/capture.c

@@ -384,7 +384,7 @@ static float _calc_auto_radius(float *const in,
               : _calcRadiusXtrans(input, width, height, xtrans);
 
   if(in != input) dt_free_align(input);
-  return radius;
+  return CLAMP(radius, 0.0f, 1.5f);
 }
 
 
@@ -620,38 +620,37 @@ static void _capture_radius(dt_iop_module_t *self,
 {
   dt_iop_demosaic_params_t *p = self->params;
   const dt_image_t *img = &self->dev->image_storage;
-  const gboolean enough = ((float)width / (float)img->p_width) > 0.6f
-                      &&  ((float)height / (float)img->p_height) > 0.6f;
+  const gboolean reliable = ((float)width / (float)img->p_width) > 0.5f
+                      &&  ((float)height / (float)img->p_height) > 0.5f;
+  const gboolean enough = width > 200 && height > 200;
 
   dt_iop_demosaic_data_t *d = piece->data;
   dt_iop_demosaic_gui_data_t *g = self->gui_data;
   const dt_dev_pixelpipe_t *pipe = piece->pipe;
   const gboolean fullpipe = pipe->type & DT_DEV_PIXELPIPE_FULL;
   const dt_iop_buffer_dsc_t *dsc = &pipe->dsc;
-  const float radius = 0.01f * (int)(enough ? 100.0f * _calc_auto_radius(in, width, height, filters, xtrans, dsc) : 10);
-  const gboolean valid = radius > 0.1f && radius < 1.5f;
+  const float radius = 0.01f * (int)(enough ? 100.0f * _calc_auto_radius(in, width, height, filters, xtrans, dsc) : 50);
   const gboolean same_radius = feqf(p->cs_radius, radius, CAPTURE_GAUSS_FRACTION);
 
   dt_print_pipe(DT_DEBUG_PIPE, filters != 9u ? "bayer autoradius" : "xtrans autoradius",
       pipe, self, DT_DEVICE_NONE, NULL, NULL,
-      "%sradius=%.2f from %s is %svalid",
-      same_radius ? "unchanged" : "", radius, enough ? "enough" : "small", valid ? "" : "not ");
+      "%sradius=%.2f from %s image data is %s reliable",
+      same_radius ? "unchanged" : "", radius,
+      enough ? "enough" : "small",
+      reliable ? "" : "not ");
 
-  if(fullpipe)
+  if(fullpipe && g)
   {
-    if(valid && !same_radius)
+    g->autoradius = TRUE;
+    if(!same_radius || g->new_radius < 0.0f)
     {
       p->cs_radius = radius;
-      if(g)
-      {
-        g->new_radius = radius;
-        g->autoradius = TRUE;
-      }
+      g->new_radius = radius;
     }
-    if(!enough)
-      dt_control_log(_("can't calculate a reliable capture radius as you are zoomed in too much"));
+    if(!reliable)
+      dt_control_log(_("imprecise radius calculation due to cropping or because you are zoomed in too much"));
   }
-  d->cs_radius = valid ? radius : 0.5f;
+  d->cs_radius = radius;
 }
 
 static void _capture_noise(dt_iop_module_t *self,
@@ -668,13 +667,13 @@ static void _capture_noise(dt_iop_module_t *self,
   dt_print_pipe(DT_DEBUG_PIPE, "capture threshold",
       pipe, self, DT_DEVICE_NONE, NULL, NULL, "threshold=%.2f", thrs);
 
-  if(fullpipe && !same_thrs)
+  if(fullpipe && g)
   {
-    p->cs_thrs = thrs;
-    if(g)
+    g->autothrs = TRUE;
+    if(!same_thrs)
     {
+      p->cs_thrs = thrs;
       g->new_thrs = thrs;
-      g->autothrs = TRUE;
     }
   }
   d->cs_thrs = thrs;
@@ -710,7 +709,7 @@ static inline gboolean _radius_requested(dt_iop_module_t *self,
   // do we require a calculation of the capture radius?
 
   // if the calc-radius button in UI has been clicked
-  if(g && (g->new_radius < 0.0f)) return TRUE;
+  if(g && fullpipe && (g->new_radius < 0.0f)) return TRUE;
 
   // if running in gui the first fullpipe for this image and there is an invalid radius
   if(g && fullpipe && !g->autoradius && invalid_radius) return TRUE;