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Old 09-20-2012, 11:12 PM   #24
willus
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Mod to make PDF OCR text visible

Quote:
Originally Posted by frostschutz View Post
I don't know what to edit to make the text visible though. You'd have to replace the font somehow but how? Might have a go at willus PDF later to see what he changed :P
If you decompress the PDF object stream that renders the OCR text, you'll see this line (or these two tokens) near the beginning of the stream:

3 Tr

"Tr" stands for Text Render, and 3 means invisible. If you change the 3 to a 0, the text becomes visible. The only tricky part is decompressing the stream since it's usually compressed. See p. 246 of Adobe's PDF Reference.
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