Workflow Guide region segmentation

In this processing step, an (optimized) document image is taken as an input and the image is segmented into the various regions, including columns. Segments are also classified, either coarse (text, separator, image, table, ...) or fine-grained (paragraph, marginalia, heading, ...).

Note: If you use ocrd-tesserocr-segment-region, which uses only bounding boxes instead of polygon coordinates, then you should post-process via ocrd-segment-repair with plausibilize=True to obtain better results without large overlaps.

Note: The ocrd-sbb-textline-detector and ocrd-cis-ocropy-segment processors do not only segment the page, but also the text lines within the detected text regions in one step. Therefore with those (and only with those!) processors you don't need to segment into lines in an extra step.

Available processors

Processor	Parameter	Remarks	Call
ocrd-tesserocr-segment-region	-P find_tables false	Recommended	ocrd-tesserocr-segment-region -I OCR-D-DEWARP-PAGE -O OCR-D-SEG-REG
ocrd-segment-repair	-P plausibilize true	Only to be used after ocrd-tesserocr-segment-region	ocrd-segment-repair -I OCR-D-SEG-REG -O OCR-D-SEG-REPAIR -P plausibilize true
ocrd-sbb-textline-detector	-P model /path/to/model	Models can be found here; For model you need to pass the local path on your hard drive as parameter value.	ocrd-sbb-textline-detector -I OCR-D-DEWARP-PAGE -O OCR-D-SEG-LINE -P model /path/to/model
ocrd-cis-ocropy-segment	-P level-of-operation page		ocrd-cis-ocropy-segment -I OCR-D-DEWARP-PAGE -O OCR-D-SEG-LINE -P level-of-operation page
ocrd-anybaseocr-block-segmentation	-P block_segmentation_model /path/to/mrcnn -P block_segmentation_weights /path/to/model/block_segmentation_weights.h5	For available models take a look at this site; you need to pass the local path on your hard drive as parameter value.	ocrd-anybaseocr-block-segmentation -I OCR-D-DEWARP-PAGE -O OCR-D-SEG-REG -P block_segmentation_model /path/to/mrcnn -P block_segmentation_weights /path/to/model/block_segmentation_weights.h5
ocrd-pc-segmentation			ocrd-pc-segmentation -I OCR-D-DEWARP-PAGE -O OCR-D-SEG-REG

Notes on parameter usage

E.g.

• which parameters do you use with what values?
• which parameters are insufficiently documented?
• which aspects of a processor should be parameterizable but are not?

Notes on document-specific usage

E.g. which processors worked best with what material? -- feel free to post sample images here, too.