deskew:auto-crop= true, auto crop the image after deskewing. delegate:bimodal= true, Specifies direct conversion from Postscript to PDF. distort:scale= value. The documentation page doesn’t include an entry for “%[deskew:angle]”. I suggest. Hi, I’m want to extract street signs from photographs and deskew them, but I don’t know where to begin. Deskewing I believe is the easy part.
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My scripts are available free of charge for non-commercial non-profit use, ONLY. For use of my scripts in commercial for-profit imagemmagick or non-free applications, please contact me Fred Weinhaus for licensing arrangements.
My email address is fmw at alink dot net. Usage, whether stated or not in the script, is restricted to the above licensing arrangements.
It is also subject, in a subordinate manner, to the ImageMagick license, which can be found at: Please read the Pointers For Use on my home page to properly install and imagemagik my scripts. Unrotates deskews an image containing text. If the meta data contain orientation information, then the image will be auto-oriented first.
The image is converted to the FFT spectrum image and a list of peaks orthogonal to the rows of text are located. From the list of peak coordinates a least square fit to a line is computed and the orientation of the line is used to get the unrotation angle. The approach will not be able to determine whether the text is right side up or up side down.
Deskew – ImageMagick
However, it should properly correct for rotations in the range of -n number Any valid IM metric imaggemagick be used. This option is only needed for Imagemagick versions less than 6. This is used since the center of the FFT spectrum is brighter than the outer regions. Attenuation linearly ramps from the center to no attenuation at the edges of the spectrum.
Attenuating the center allows a longer linear distribution of found peaks, which helps to better define deskeew orientation line.
Command-line Options @ ImageMagick
However, it may introduce more off-linear false peaks. Shorter lengths of text may require a different attenuation.
COLOR is the background color for deskewed image. Any valid IM color is allowed. An optional output image may be specified which will be the masked FFT spectrum showing the locations of the peaks that define the line from which the unrotation angle is determined.
No guarantee that this script will work on all platforms, nor that trapping of inconsistent parameters is complete and foolproof. Use At Your Own Risk.
To unrotate deskews an image containing text. Some versions of Imagemagick around 6. What the script does is as follows: