Deskew developed by Marek Mauder is a post-scanning utility for de-skewing scanned images of text.
Deskew is offered in two interaction modes: a CLI component that can be run in console mode, and a GUI layer that calls the deskew.exe
Github page: https://github.com/galfar/deskew
Web page: https://galfar.vevb.net/wp/projects/deskew/
There are versions for Win32, Win64, ARM, MacOS and Linux.
The current version for Win64 is v.1.30
Download link for "deskew": https://github.com/galfar/deskew/releas ... w-1.30.zip
Download link for the "GUI": https://github.com/galfar/deskew/releas ... i-0.90.zip
Usage of the CLI version (from the github page https://github.com/galfar/deskew ):
deskew [-o output] [-a angle] [-b color] [..] input
input: Input image file
Options:
-o output: Output image file (default: out.png)
-a angle: Maximal expected skew angle (both directions) in degrees (default: 10)
-b color: Background color in hex format RRGGBB|LL|AARRGGBB (default: black)
Ext. options:
-q filter: Resampling filter used for rotations (default: linear,
values: nearest|linear|cubic|lanczos)
-t a|treshold: Auto threshold or value in 0..255 (default: a)
-r rect: Skew detection only in content rectangle (pixels):
left,top,right,bottom (default: whole page)
-f format: Force output pixel format (values: b1|g8|rgb24|rgba32)
-l angle: Skip deskewing step if skew angle is smaller (default: 0.01)
-g flags: Operational flags (any combination of):
c - auto crop, d - detect only (no output to file)
-s info: Info dump (any combination of):
s - skew detection stats, p - program parameters, t - timings
-c specs: Output compression specs for some file formats. Several specs
can be defined - delimited by commas. Supported specs:
jXX - JPEG compression quality, XX is in range [1,100(best)]
tSCHEME - TIFF compression scheme: none|lzw|rle|deflate|jpeg|g4
Supported file formats
Input: BMP, JPG, PNG, JNG, GIF, DDS, TGA, PBM, PGM, PPM, PAM, PFM, TIF, PSD
Output: BMP, JPG, PNG, JNG, GIF, DDS, TGA, PGM, PPM, PAM, PFM, TIF, PSD
Usage of the GUI version (Win64):
- Extract Deskew-1.30.zip and DeskewGui-0.90.zip in empty folders
- In the folder containing the unzipped Deskew-1.30.zip, look for the Bin folder and inside this Bin folder, take a copy the executable "deskew.exe" and paste it to an empty folder named "whatever_name_U_want"
- In the folder containing DeskewGui-0.90.zip, take a copy of the executable "deskewgui.exe" and paste it into the "whatever_name_U_want" folder.
- To run the utility, just click on deskewgui, and drag-n-drop the file to the UI
Portability:
I moved around my "whatever_name_U_want" folder, and I always was able to run the utility (not really surprising !!!!), as for crumbs left in the registry ... mea culpa, I did not check.
Evaluation (as of this writing):
Nice tool that can come handy if you want to straighten automatically (I mean, without having to provide the rotation angle) one or two pages (files).
I did not test the tool extensively.
However I noticed that - at least in GUI mode - the output file of a Black & White input file is in fact a Gray TIF ..../ This is a bit annoying ... unless you take the trouble of copying the content of your gray file into the original B&W file, which is doable for a couple of files, otherwise use Scantailor ( viewtopic.php?p=101448&hilit=Scantailor#p101448 ).