ImageMagick convert scan: Difference between revisions
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[[Category:Ubuntu Images]] | [[Category:Ubuntu Images]] | ||
[[Category:201612]] | [[Category:201612]] | ||
= 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. | 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. | ||
<syntaxhighlight lang=bash> | <syntaxhighlight lang=bash> | ||
convert '*.jpg' -set filename:f '%t(resized).%e' -resize 1500x -quality 85 '%[filename:f]' | convert '*.jpg' -set filename:f '%t(resized).%e' -resize 1500x -quality 85 '%[filename:f]' | ||
</syntaxhighlight> | </syntaxhighlight> | ||
= 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. | |||
<syntaxhighlight lang=bash> | |||
convert '*.jpg' -set filename:f '%t(resized).%e' -white-threshold 92% -resize 1500x -quality 80 '%[filename:f]' | |||
</syntaxhighlight> | |||
= 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. | 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. | ||
<syntaxhighlight lang=bash> | <syntaxhighlight lang=bash> | ||
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</syntaxhighlight> | </syntaxhighlight> | ||
Also see | = Split up picture = | ||
<!-- divide split --> | |||
When you scan all your old photos, four at a time, you can use this to divide them up in quarters. | |||
<syntaxhighlight lang=bash> | |||
#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]' | |||
</syntaxhighlight> | |||
= Also see = | |||
* [[ImageMagick tools]] | * [[ImageMagick tools]] | ||
Revision as of 18:56, 3 April 2017
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]'
