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--- pdfwarez [2018-11-23 19:02:47] – created - external edit 127.0.0.1
+++ pdfwarez [2025-10-20 18:01:09] (current) – jenda
@@ Line 1: / Line 1: @@
 ====== Creating a searchable scanned and OCR'd book ======
+===== General PDF instructions (involves some resampling) =====
+Work in empty directory
+<code>
+mkdir foo
+cd foo
+</code>
+Separate to individual pages
+<code>
+pdfseparate ../foo.pdf separated-%05d.pdf
+</code>
+Render to PNG:
+<code>
+for f in separated-*pdf; do t=${f#separated-}; echo convert -density 300 $f rendered-${t%.pdf}.png ; done  | parallel
+</code>
+OCR:
+<code>
+export OMP_THREAD_LIMIT=1
+for f in *.png; do t=${f#rendered-}; echo tesseract -c textonly_pdf=1 --oem 1 --dpi 300 -l eng $f ocr-${t%.png} pdf; done  | parallel
+</code>
+Combine originals + OCR text layer:
+<code>
+for f in ocr-*.pdf; do t=${f#ocr-}; pdftk separated-$t background ocr-$t output combined-$t; done
+</code>
+Produce final output:
+<code>
+pdfunite combined*.pdf output.pdf
+</code>
+===== Old instructions - one image per page =====
 Prerequisites: