slnkahveci commented on code in PR #1883:
URL: https://github.com/apache/systemds/pull/1883#discussion_r1331405317


##########
scripts/builtin/img_crop_linearized.dml:
##########
@@ -0,0 +1,64 @@
+#-------------------------------------------------------------
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+#
+#-------------------------------------------------------------
+
+# The img_crop_linearized cuts out a rectangular section of multiple 
linearized images.
+#
+# INPUT:
+# 
----------------------------------------------------------------------------------------
+# img_in    Linearized input images as 2D matrix
+# w         The width of the subregion required
+# h         The height of the subregion required
+# x_offset  The horizontal coordinate in the image to begin the crop operation
+# y_offset  The vertical coordinate in the image to begin the crop operation
+# 
----------------------------------------------------------------------------------------
+#
+# OUTPUT:
+# 
--------------------------------------------------------------------------------------------------
+# img_out  Cropped images as linearized 2D matrix
+# 
--------------------------------------------------------------------------------------------------
+
+m_img_crop_linearized = function(Matrix[Double] img_in, Integer w, Integer h, 
Integer x_offset, Integer y_offset, Integer s_cols, Integer s_rows) return 
(Matrix[Double] img_out) {
+  
+  orig_w = s_cols
+  orig_h = s_rows
+
+  nrows = nrow(img_in) # number of images
+
+  start_h = (ceil((orig_h - h) / 2)) + y_offset
+  end_h = (start_h + h - 1) 
+  start_w = (ceil((orig_w - w) / 2)) + x_offset
+  end_w = (start_w + w - 1) 
+
+  if((start_h < 0) | (end_h > orig_h) | (start_w < 0) | (end_w > orig_w)) {
+    print("Offset out of bounds! Returning input.")
+    img_out = img_in
+  }
+  else {
+    mask = matrix(0, rows=orig_h, cols=orig_w)
+    temp_mask = matrix(1, rows=h , cols=w )
+    mask[start_h:end_h, start_w:end_w] = temp_mask
+
+    linear_mask = matrix(mask, rows=1, cols=orig_w * orig_h)
+    
+    img_out = matrix(removeEmpty(target=(matrix(img_in+1, nrow(img_in), 
ncol(img_in))), margin="cols", select=linear_mask) - 1, nrows, w * h)

Review Comment:
   Slicing out causes runtime errors and flakes for larger images/wider inputs 
(e.g. the last test parameters). I think restoring it to removeEmpty is a 
better option.



-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: [email protected]

For queries about this service, please contact Infrastructure at:
[email protected]

Reply via email to