warn if passing raw images to single-channel models

ocrd_calamari/recognize.py

@@ -31,6 +31,14 @@ class CalamariRecognize(Processor):
         checkpoints = glob(self.parameter['checkpoint'])
         self.predictor = MultiPredictor(checkpoints=checkpoints)
 
+        self.input_channels = self.predictor.predictors[0].network.input_channels
+        #self.input_channels = self.predictor.predictors[0].network_params.channels # not used!
+        # binarization = self.predictor.predictors[0].model_params.data_preprocessor.binarization # not used!
+        # self.features = ('' if self.input_channels != 1 else
+        #                  'binarized' if binarization != 'GRAY' else
+        #                  'grayscale_normalized')
+        self.features = ''
+
         voter_params = VoterParams()
         voter_params.type = VoterParams.Type.Value(self.parameter['voter'].upper())
         self.voter = voter_from_proto(voter_params)
@@ -54,17 +62,30 @@ class CalamariRecognize(Processor):
             pcgts = page_from_file(self.workspace.download_file(input_file))
 
             page = pcgts.get_Page()
-            page_image, page_xywh, page_image_info = self.workspace.image_from_page(page, page_id)
+            page_image, page_coords, page_image_info = self.workspace.image_from_page(
+                page, page_id, feature_selector=self.features)
 
-            for region in pcgts.get_Page().get_TextRegion():
-                region_image, region_xywh = self.workspace.image_from_segment(region, page_image, page_xywh)
+            for region in page.get_TextRegion():
+                region_image, region_coords = self.workspace.image_from_segment(
+                    region, page_image, page_coords, feature_selector=self.features)
 
                 textlines = region.get_TextLine()
                 log.info("About to recognize %i lines of region '%s'", len(textlines), region.id)
-                for (line_no, line) in enumerate(textlines):
-                    log.debug("Recognizing line '%s' in region '%s'", line_no, region.id)
-
-                    line_image, line_xywh = self.workspace.image_from_segment(line, region_image, region_xywh)
+                for line in textlines:
+                    log.debug("Recognizing line '%s' in region '%s'", line.id, region.id)
+
+                    line_image, line_coords = self.workspace.image_from_segment(
+                        line, region_image, region_coords, feature_selector=self.features)
+                    if ('binarized' not in line_coords['features'] and
+                        'grayscale_normalized' not in line_coords['features'] and
+                        self.input_channels == 1):
+                        # We cannot use a feature selector for this since we don't
+                        # know whether the model expects (has been trained on)
+                        # binarized or grayscale images; but raw images are likely
+                        # always inadequate:
+                        log.warning("Using raw image for line '%s' in region '%s'",
+                                    line.id, region.id)
+                    
                     line_image_np = np.array(line_image, dtype=np.uint8)
 
                     raw_results = list(self.predictor.predict_raw([line_image_np], progress_bar=False))[0]