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Questions tagged [vips]

`libvips` is a fast image processing library with low memory needs. `vips` is the command-line tool for that library.

libvips is a fast image processing library with low memory needs.

vips is the command-line tool for that library.

179 questions
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Remove color cast using libvips

I have sRGB images with color casts. To remove it manually I usually use Photoshop Level Adjustments. Photoshop also have tools for that: Auto Contrast or even better Auto Tone which also takes shadows, midtones & highlights into account. If I…
groboter
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How to add spacing between characters in text using VIPS?

I'm using the VIPS library for manipulating images and adding text to them. I want to know how to add spacing to characters in text? The following image is an example of what I'm talking about.
PiFace
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How to prevent Pyvips from stretching images

I'm trying to join multiple images together using pyvips, but during the process the width of the image more than doubles, and I can't seem to figure out why Here's the key part of my code: files = ['small_images\\'+filename for filename in…
Jayleaf
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how can I load a single tif image in parts into numpy array without loading the whole image into memory?

so There is a 4GB .TIF image that needs to be processed, as a memory constraint I can't load the whole image into numpy array so I need to load it lazily in parts from hard disk. so basically I need and that needs to be done in python as the project…
Koustav Chanda
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Dzi Viewer using CPP

I am looking for a Deep Zoom Image (DZI) viewer in CPP. Currently, we have a viewer designed in javascript (Open Seadragon), java, and C# for the dzi images. I am looking for the open-source viewer that can be integrated in my CPP application.
Hacker_Sam
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Compare images line by line using vips

Background: I have images I need to compare for differences. The images are large (on the order of 1400x9000 px), machine-generated and highly constrained (screenshots of a particular piece of linear UI), and are expected to be nearly identical,…
mathrick
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Where to invoke VIPS_INIT in a C shared library

I am working on a C shared library that would contain one function that receives a filename, and returns a pointer to the C-array representation of the image. I read VIPS_INIT needs to be set in the beginning of the program, with argv[0] as its…
linkyndy
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Ruby VIPS image.write_to_memory yields different results in different environments

We need to open an image and write its pixels to memory, so a C library can further process it. We're doing this with the lines below: image = Vips::Image.new_from_file(filename) pixels_pointer = image.write_to_memory However, it seems that what's…
linkyndy
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Can't find configure file

I'm trying to build libvips from source tarball and following the instructions. https://jcupitt.github.io/libvips/install.html It's suppose to be a basic "./configure" "make" "make install" procedure, but there is no "configure" file in the source…
hamochi
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I'm trying to verify/fix the cause of unknown action "pdfload" from libvips

I am using a Heroku vips buildpack. I would like to confirm that vips: unknown action "pdfload" means libvips was compiled without poppler being available so I can't open pdfs. Is that true?
Brandon
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I can't get libvips to compile on heroku

I have spent days trying to get the outdated libvips buildpacks working on Heroku. I finally got https://github.com/wwarne/heroku-buildpack-vips to work, but it doesn't seem to have been compiled with libpoppler, so I don't have pdf support which I…
Brandon
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libvips extract area of NDPI from Ex40 not from map

I am using libvips to get pyramids of .ndpi images. through this answer and searching the documentation I found this command vips extract_area myimage.ndpi[level=0] mypyramid.dz 0 0 10000 10000 Which extracts a crop starting at 0 0 and size 10000…
lesolorzanov
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Compose lots of images at once in imagemagick Ruby

I have the following code which takes a PDF file and composes it into a single jpg image which has a horizontal black line between each PDF page image, stacking the PDF pages. image = MiniMagick::Image.open(pdf_file) # create a new blank file which…
Brandon
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Tiling of large numer of images using database

I have coordinates in a numpy array of all the images which needs to be joined. I have used OpenCV to find the coordinates using normalized cross-correlation. I am having a problem in tiling those images as it is very large 300X300 images of…
shivam chaubey
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How to achieve a BW negative in ruby-vips

I have a png with the outline of an irregularly shaped object which I want to turn into a mask. I need to floodfill the interior with black, and then swap black and white. It's 8-bit grayscale, with values of 0 and 255 only. I can't fill the…
Robert Schaaf
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