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Questions tagged [image-processing]

168 questions
348
votes
14 answers

How to get information about an image (picture) from the Linux command-line?

I'm working on a web app and currently migrating some stuff from an old app, but I hate that I have to open an image editor to get some info about images I'm migrating. Things like image dimensions. Is there a command line tool I can use for such…
JWL
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249
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2 answers

Vertically stack multiple images using ImageMagick

I would like to combine multiple images into one image using ImageMagick. To explain a little better, I want the result to look similar to this: That is, I have a number of screenshots, and I want to turn them into one image with the original…
Petter
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157
votes
14 answers

How to prove the authenticity of a screenshot?

I have take some screenshots of chat from Whatsapp web using Windows 8 Snipping Tool. I saved those images in PNG format. Now I want to prove that those images are the original, not tampered or edited. Can you please let me know how can I prove…
Optimus
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116
votes
3 answers

Using GIMP, what is the easiest way to repeat an image in a tiled fashion?

I have an image that is 100×125 pixels in size. I'd like to create a new image by repeating the source image, five times, horizontally (so the new image is 500×125px). The repetitions must be pixel perfect, in exactly the right place (so I'm less…
Jon-Eric
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80
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16 answers

How can I combine 30,000 images into a timelapse movie?

I have taken 30,000 still images that I want to combine into a timelapse movie. I have tried QuickTime Pro, TimeLapse 3, and Windows Movie Maker, but with such a huge amount of images, each of the programs fail (I tried SUPER ©, but couldn't get it…
Swift
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59
votes
4 answers

How to crop an image using ImageMagick from the command line?

I am trying to crop a 640x640 image using ImageMagick on the command line. I need to remove about 20 pixels from the bottom part of the image all the way from left to right. A long strip along the bottom. I know about the shave command. What would…
user2041357
54
votes
5 answers

I want to change DPI with ImageMagick without changing the actual byte-size of the image data

In GIMP there is a very simple way to do what I want. I only have the German dialog installed but I’ll try to translate it. I’m talking about going to Picture -> PrintingSize and then adjusting the Values X-Resolution and Y-Resolution which are…
Boris Däppen
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42
votes
3 answers

Is there a generic mime-type for all image files?

I know that I can use the specific mime-types as listed for example here, or a generic mime-type for any file like application/octet-stream, but is there a generic mime-type for all image files? (I want to edit a .desktop file in Linux Mint KDE to…
user162573
35
votes
9 answers

Photoshop: Trim a photo so it contains no transparent pixels?

In Photoshop, I've put together some panorama photos using the Photomerge tool, and the resulting image contains a lot of transparent pixels. Also, because it's assembled from multiple photos, the alignment can be off. What I'd like to do is cut the…
nickf
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31
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10 answers

How to print documents to pictures (gif, bmp etc.) on windows

What is the easiest way to capture the printout of a document in a picture (i.e. GIF, BMP etc.)? Making a screenshot does not help, since the printout is different and larger than the screen. Is there a special printer driver for windows that…
Dr. Hans-Peter Störr
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14
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7 answers

What is the best method to remove duplicate image files from your computer?

I have a lot of duplicate image files on my Windows computer, in different subfolders and with different file names. What Python script or freeware program would you recommend for removing the duplicates? (I've read this similar question, but the…
BioGeek
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11
votes
4 answers

How to get a good clean newspaper scan?

I tried a few times to scan newspaper articles, but the images I got were always blotchy and with bad colors, sort of like this: Sometimes I see some really good scans, like this: What is the trick to get such good results? Do I need a…
itsadok
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10
votes
7 answers

Detecting blank image files

I am using scanimage with a document scanner (Canon DR-2510C) that supports duplex scanning. Unfortunately, its SANE driver does not support blank page detection, so that with mixed pages (single/double-sided), blank pages make it into the scan…
Thilo-Alexander Ginkel
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9
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2 answers

Auto-crop black margins dynamically of scanned images?

I have a notebook photocopied and the photocopy scanned, about 200 pages. For various reasons I need to print this material. There are large amounts of black areas at the sides of the page (after the page itself ends), "black margins". The image…
n611x007
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9
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4 answers

How to resize an animated webp？

I want to be able to change the size of a dynamic webp. Sample picture. I found this website to do just that. So how can I implement something similar in my own program? I tried using ImageMagick7 or ffmpeg5, but failed. Environment: cat…
shsf
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