ImageMagick convert scan

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Revision as of 18:56, 3 April 2017 by Wilbert (talk | contribs)


Text document resize and quality

After scanning a document you may want to resize and compress the resulting image. You should scan with a higher resolution so you can have a better-quality lower resolution.

convert '*.jpg' -set filename:f '%t(resized).%e' -resize 1500x -quality 85 '%[filename:f]'

Text document white threshold

The white paper background will probably not end up being white so we add a 'white-threshold'. A lower value will mean more light areas are converted to pure white.

convert '*.jpg' -set filename:f '%t(resized).%e' -white-threshold 92% -resize 1500x -quality 80 '%[filename:f]'

White threshold

The white paper background will probably not end up being white so we add a 'white-threshold'. A lower value will mean more light areas are converted to pure white.

convert '*.jpg' -set filename:f '%t(resized).%e' -white-threshold 92% -resize 1500x -quality 80 '%[filename:f]'

Split up picture

When you scan all your old photos, four at a time, you can use this to divide them up in quarters.

#divide picture into quarters with a 4 pixel overlap
convert "*.jpg" -set filename:f '%t(%d)(resized).%e' -crop 2x2+4+4@ +repage +adjoin '%[filename:f]'

Also see