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Questions tagged [chunkypng]

14 questions
8
votes
1 answer

How to modify the color of images to remove vibrancy?

How I can change the colors from this: into this: I generated the output image using Gimp with the input image as layer one, and the background color from the image as layer two, in the Layers panel I selected the mode "colors" I want preserve the…
astropanic
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4
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2 answers

How to differentiate between a pixel with no color and a black pixel?

I am using ChunkyPNG in order to get the colors of pixels on images. When an image has no background color at all, and is rendered into a browser, the background color will become white (usually, depending on your browser configuration). My…
Johnny Red
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0
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1 answer

Chunky PNG Image comparison- How to highlight multiple Differences

I've just discovered this article, which talks about comparing two images in Ruby and highlighting the differences. But if I have images with multiple differences, e.g.: one difference is in the header and the other in the footer it will draw a…
Anubala Vashisht
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0
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2 answers

How do I get the hex value from each pixel in RMagick or Chunky_PNG?

I'm trying to read the value of each pixel as hex (HTML notation) using RMagick or Chunky_PNG e.g. #5DBCD2. At the moment I have the below which kind of does what I want but I couldn't find the right way to actually read the hex value. I'd prefer to…
ant
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0
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0 answers

Can't identify a Stack level too deep error on rake task with recursive function

I have a big problem with a "Stack level too deep" error on my rake script. This script basically read an image that contains some pixels with value "-1". So I use a recursive function when found a "-1" value to analize their neightbors and save it…
jgiunta
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0
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1 answer

ChunkyPNG: Is it possible to read an image directly from a URL?

I tried (with some success) require 'open-uri' require 'chunky_png' image_url = "http://res.cloudinary.com/houlihan-lokey/image/upload/c_limit,h_75,w_120/ixl7z4c1czlvrqnbt0mm.png" # image_url =…
aaandre
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0
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1 answer

Using Qrio with rails. Works fine when i use it with ruby files, not working with rails

I want to decode QR codes in my rails app. I am using Qrio gem which needs ChunkyPng gem to work. It is working fine when i write and run a ruby program using it. But, when i try using it with Rails it does not work. This isthe error i get. No such…
Anil Dukkipatty
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0
votes
1 answer

Corp image with ruby

I try to corp an image how you can see in my last line of code i trigger: p.corp!(0,0,p.width,black_last).save('bearbeitet.png') But somehow i get this error: bild.rb:29:in `
': undefined method `corp!' for #…
John Smith
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0
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1 answer

Standard deviation with ChunkyPNG

I am trying to find the contrast of an image using ChunkyPNG. Is there any way to get the standard deviation of an image using ChunkyPNG?
Hommer Smith
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0
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1 answer

Requiring gem in Ruby on Rails - OilyPNG vs ChunkyPNG

I am currently using ChunkyPNG, but I want to give OilyPNG a try. I have tried using it in a simple ruby script and the performance is much better. I basically install both gems in the Gemfile and require 'oily_png' in my script. However, in my RoR…
Hommer Smith
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0
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1 answer

Crop logo from Sprite using CSS attributes

Given a sprite, for example, StackOverflow sprite and CSS attributes such as: background-position: 0px 0px; width: 250px; height: 61px; I am able to crop the logo of the sprite with Chunky PNG library. However, some sites, have negative…
Hommer Smith
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0
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2 answers

A while loop in a while loop in ruby

I'm relativly new to Ruby, or Programming at all, so please excuse me, if i'm making a "noob2 mistake with the logic here. I am trying to get an output of rgba pixel values in binary for every pixel in an image (and it's location), using…
x3nu
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1 answer

Understanding and Converting Ruby's ChunkyPNG to Javascript Equivalent

I am converting some RUBY code into Javascript. This RUBY code uses ChunkyPNG Ruby Library. Here is the Ruby Code: def self.from_png(file) image = ChunkyPNG::Image.from_file(file) mask = Mask.new(image.height, image.width) mask.rows.times do…
preston
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-1
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1 answer

When I try to map out pi in colors with ChunkyPNG, I get many unexpected results

I am trying to calculate pi and put it into a picture in ruby. It works up until lines 36 (where it doesn't write pi [without a decimal place] to file) and 63 (where it only writes the off white color to pi.png). As a side note, the program doesn't…
Jake L.
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