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Questions tagged [libpng]

libpng is the official PNG reference library, supporting most all of PNG's features, is extensible, and has been widely used and tested for over twenty years.

libpng is the official PNG reference library, that allows you to read, manipulate and write .png datastreams. It supports almost all PNG features, is extensible, and has been extensively tested for over twenty years.

libpng is a platform-independent library containing ANSI C (C89) source code. It requires zlib 1.0.4 or later (1.2.8 or later recommended) to be used.

For more information, visit the libpng website, sourceforge.io page where the source is available, the libpng manual or the Wikipedia page.

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Exploiting redundancy among JPG images

I wish to exploit redundancy among a set of similar colored JPG images. Set redundancy compression has been used successfully for similar 8-bit grayscale images. They basically find the MAX and MIN of a set of images and encode the original images…
user655617
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Website API giving fatal libpng error

Hello so I'm currently working on a program that will upload an image to my website using the POST method and it's API. Right now everything is going fine and it is connecting to the server and trying to transfer the image however it never actually…
user1938398
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Creating 2bits color depth PNG images with Libpng

I would like to generate PNG images with 1bits (2 colors) or 2bit (4 colors) depth with the library Libpng. Does any one know how to do it ? I have tested examples, and they all seem to work with 8bit color depth ? I know png_set_IHDR but in the…
jo2s
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Using libpng filters

I want to read a PNG file with libpng and I want to use the filter png_set_rgb_to_gray_fixed to convert RGB values into grayscale. The original image has 8 bits per channel, hence 3 bytes per pixel. I expect the output to be 8 bit per pixel. However…
Emanuele Paolini
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ImageMagick : Extractng images from PSD

I'm trying to extract images from my PSD using this command : convert my_file.psd extracted/image-%d.png The problem is some pictures are perfectly extracted, but about 60% are not. Here is a sample of what I get :…
user1319182
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libpng error: Read Error

I has some png image. I open it. Than i save it to file. And when i try to open saved image i have the problem. libpng error: Read Error on png_read_rows Here is the writing code: png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,…
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BitmapData size in windows mobile

I am trying to read image using native functions. To that end, i tried using this code: var result = new Bitmap((int)info.width,(int)info.height,PixelFormat.Format24bppRgb); var data = result.LockBits(new Rectangle(0, 0,…
Srv19
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libpng ndk-build internal compiler error in debug mode

I use ndk-build to compile libpng source code in debug mode, then it shows “internal compiler error” in pngrtran.c. But when I compile in release mode, it can success. Is this a bug in libpng? How I can resolve this?
bitristan
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Error when compiling libpng in visual studio 2008

lI am trying to use libpng in program, working on Windows Mobile 6.1. To that end i created a c++ project from template "c++ SmartDevice Class library", and added to it appropriate c source files from libpng, using visual studio project provided…
Srv19
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Undefined references in png++

I am new to C++ on linux enviroment and am trying to use the png++ library for a project. The problem I am facing is that that a simple program I write using png++ incudes does not work and shows me the following errors AProg.o: In function…
mu_sa
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ming 0.4.2 compilation errors on Ubuntu 12.04 when installing from source code

I am trying to install ming 0.4.2 from source code and it was compilable before on Ubuntu 10.04, but now it' giving following compilation errors when I try to install using command sudo make install (libpng is already installed). /bin/bash…
gmuhammad
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C++, Allegro, Ubuntu, and libpng/LoadPNG

I've been looking around for quite a while, but I haven't quite been able to hit on a source answering my question. I want to use PNGs with Allegro. I know about libpng and loadpng for Allegro, but I don't know what to do with these. Obviously, I'm…
Ben Dixon
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libpng: writing a png fails: stops at header write error

I can't figure out what is wrong. When I try to write the PNG, I get an error: "Error during writing header". Do I need to include something else? I took the .lib/.h files from here: http://www.eden.net.nz/7/20071024/ Edit: I finally managed to…
Rookie
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Crash in png_set_read_fn() on Windows 7

I'm cross-compiling some C code for Windows 7 and linking to libpng12.dll found here. Unfortunately, the line below causes a crash (GDB says segmentation fault): png_structp png = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); I'm…
andyvn22
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Loading image with libpng produces unexpected pixel data

I have problems trying to load png file into my application. It seems to load headers fine, and recognize that image is png, but for some reason the output has the same values, though image is really not one color. Another thing that bugs me is that…
SMGhost
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