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About this collection

This test collection contains a selection of ten maps from the Historical California Topographical Maps collection (which contains over 700 maps of California quadrangle maps issued by the United States Geological Survey).

This small set of ten maps contains full-text metadata generated by Strabo (optical character recognition) rather than ABBYY FineReader (which generated the full text for the larger collection of over 700 maps). Strabo is software developed by USC Professor Yao-Yi Chiang specifically for recognizing words on maps. See Spatial technology opens a window into history.

The full-text metadata for this set of ten maps was generated using a Web service developed by Zahid Rafique. See Strabo Web Interface (beta).

Initial results from a comparison of the two OCR software packages (Strabo vs. ABBYY FineReader) on this set of ten maps demonstrate that Strabo is able to recognize 75% more characters and 78% more words of full text from these maps compared to ABBYY FineReader (via CONTENTdm). The characters and words recognized are not 100% accurate, but are generally significantly more accurate than ABBYY FineReader.

 The most dramatic difference in OCR performance is demonstrated in a map of "California. Alturas quadrangle (60'), 1886". (Scroll to the bottom of the windows at the links below to see the full text.)

  • ABBYY FineReader result: 12 characters, 1 word
  • Strabo result: 1189 characters, 255 words

This research project is a collaboration between Deborah Holmes-Wong, Zahid Rafique, and Wayne Shoaf of the USC Digital Library and Yao-Yi Chiang of the Spatial Sciences Institute at USC Dornsife College. It has been generously supported by the National Endowment for the Humanities' Preservation and Access Division under the Research and Development grant program, NVIDIA Corporation, and USC Undergraduate Research Associates Program.

 
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