ocr_crop: Find metadata region

ocr_crop.py

@@ -0,0 +1,96 @@
+# Copyright 2018 The Fuego Authors.
+#
+# Licensed 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.
+# ==============================================================================
+"""
+
+Crop given mage to get just the metadata line
+
+"""
+
+import sys
+import os
+fuegoRoot = os.path.dirname(os.path.abspath(__file__))
+sys.path.insert(0, os.path.join(fuegoRoot, 'lib'))
+sys.path.insert(0, fuegoRoot)
+import settings
+settings.fuegoRoot = fuegoRoot
+import collect_args
+import goog_helper
+import img_archive
+
+import logging
+from PIL import Image
+import numpy as np
+
+def main():
+    reqArgs = [
+        ["i", "image", "image to crop"],
+        ["o", "output", "output cropped image"],
+    ]
+    optArgs = [
+        ["m", "maxHeight", "max height of the metadata line"],
+    ]
+
+    args = collect_args.collectArgs(reqArgs, optionalArgs=optArgs, parentParsers=[goog_helper.getParentParser()])
+    maxHeight = args.maxHeight if args.maxHeight else 50
+    cushionRows = 4
+    minLetterBrightness = int(.9*255) # 90% of max value of 255
+    minLetterSize = 12
+
+    img = Image.open(args.image)
+    assert maxHeight < img.size[1]
+    try:
+        imgCroppedGray = img.crop((0, img.size[1] - maxHeight, minLetterSize, img.size[1])).convert('L')
+        croppedArray = np.array(imgCroppedGray)
+    except Exception as e:
+        logging.error('Error processing image: %s', str(e))
+        return
+
+    top = 0
+    bottom = 0
+    mode = 'find_dark_below_bottom'
+    for i in range(maxHeight):
+        row = maxHeight - i - 1
+        maxVal = croppedArray[row].max()
+        # logging.warning('Mode = %s: Top %d, Bottom %d, Max val for row %d is %d', mode, top, bottom, row, maxVal)
+        if mode == 'find_dark_below_bottom':
+            if maxVal < minLetterBrightness:
+                mode = 'find_bottom'
+        elif mode == 'find_bottom':
+            if maxVal >= minLetterBrightness:
+                mode = 'find_top'
+                bottom = row
+        elif mode == 'find_top':
+            if maxVal < minLetterBrightness:
+                possibleTop = row
+                if bottom - possibleTop > minLetterSize:
+                    top = possibleTop
+                    break
+
+    if not top or not bottom:
+        logging.error('Unable to locate metadata')
+        return
+
+    # row is last row with letters, so row +1 is first without letters, and add cushionRows
+    bottom = min(img.size[1] - maxHeight + bottom + 1 + cushionRows, img.size[1])
+    # row is first row without letters, so subtract cushionRows
+    top = max(img.size[1] - maxHeight + top - cushionRows, img.size[1] - maxHeight)
+
+    logging.warning('Top = %d, bottom = %d', top, bottom)
+    imgOut = img.crop((0, top, img.size[0], bottom))
+    imgOut.save(args.output, format='JPEG')
+
+
+if __name__=="__main__":
+    main()