Acrobat Pro includes tools that allow you to compare two PDFs to quickly spot the differences.
In Acrobat X Pro, the Document Comparison feature is available by choosing View>Compare Documents.
For a brief demonstration of this feature, click here.
Recently, I received an email from a law firm that was having trouble comparing two PDFs. The firm reported that during comparison, Acrobat couldn’t find any differences in the documents, even though visual differences were apparent during a visual inspection.
I was able to examine the documents and discovered that:
- The source documents were scanned documents
- One document was scanned in black and white. The other was scanned in greyscale.
- Documents were OCR’d
The difference in color space (black and white vs. greyscale) was enough to seriously affect Acrobat’s ability to detect changes. In effect, Acrobat saw these as being two completely different documents.
That’s probably a bug (I reported it), but we all still have a job to do. Fortunately, I was able to come up with a workaround.