Software Recommendations Stack Exchange is a question and answer site for people seeking specific software recommendations. It only takes a minute to sign up.
Sign up to join this community
Can anyone recommend gratis Windows software to automatically trim the edges of photographs of documents?
Must have an option to adjust for perspective.
The program does not need to take the actual photos.
Android apps that have this functionality include camscanner and Office Lens.
The freely available all-purpose image manipulation tool, ImageMagick, is capable of performing automatic deskewing and trimming of image files.
This tool can be invoked from a batch file to automatically deskew and crop every image in the current directory as follows:
for /r %%i in (*.png) do convert %%i -set filename:f "%t" -background
white -fuzz 50% -deskew 40% -trim +repage %[filename:f]_cropped.png
Note: there may be an error here as I am converting a Bash-script from a Linux system. Please edit my answer if you test this out.
Play with -fuzz to adjust aggressiveness of cropping and -deskew to adjust skew detection will allow you to have more control over your output.
If you want some more advanced ideas, check out "Adaptive background after rotation / deskew" and Fred's Unrotate Script.
I use Batch Image Resizer. It can batch-process hundreds of images quickly. It has autocrop action where it can automatically remove uniform or semi-uniform "background" from the sides you specify.
You can play around with tolerance to achieve optimal results. Here's the screenshot of that (all 4 sides are selected):
It is a commercial product though it's not very expensive and they frequently have sales.
Disclaimer: I have purchased this product sometime ago and am its paid user.
EDIT:
Sorry did not pay attention to "gratis" tag at first. In that case I would also say ImageMagick, though it is certainly not as straight forward to use as the software I mentioned.
