Revert "BUG: Always downsample histogram for Imviz in Plot Options (s…

…pacetelescope#2735)"

This reverts commit fbef31f.

CHANGES.rst

@@ -144,8 +144,6 @@ Cubeviz
 Imviz
 ^^^^^
 
-- Histogram in Plot Options no longer stalls for a very large image. [#2735]
-
 Mosviz
 ^^^^^^
 

jdaviz/configs/default/plugins/plot_options/plot_options.py

@@ -973,12 +973,8 @@ def _update_stretch_histogram(self, msg={}):
                 x_max = x_limits.max()
                 y_min = max(y_limits.min(), 0)
                 y_max = y_limits.max()
+
                 arr = comp.data[y_min:y_max, x_min:x_max]
-                if self.config == "imviz":
-                    # Downsample input data to about 400px (as per compass.vue) for performance.
-                    xstep = max(1, round(arr.shape[1] / 400))
-                    ystep = max(1, round(arr.shape[0] / 400))
-                    arr = arr[::ystep, ::xstep]
                 sub_data = arr.ravel()
 
             else:
@@ -999,14 +995,8 @@ def _update_stretch_histogram(self, msg={}):
                 sub_data = comp.data[inds].ravel()
 
         else:
-            if self.config == "imviz":
-                # Downsample input data to about 400px (as per compass.vue) for performance.
-                xstep = max(1, round(data.shape[1] / 400))
-                ystep = max(1, round(data.shape[0] / 400))
-                arr = comp[::ystep, ::xstep]
-            else:
-                # include all data, regardless of zoom limits
-                arr = comp.data
+            # include all data, regardless of zoom limits
+            arr = comp.data
             sub_data = arr.ravel()
 
         # filter out nans (or else bqplot will fail)