libpng

问题 I have installed freetype-2.5.3 on OS X (10.9.4) in my local directory in which I park all science software (/Users/t/Science/local), and now my other codes are running into trouble, i.e. :/Users/t> make dyld: Symbol not found: __cg_png_create_info_struct Referenced from: /System/Library/Frameworks/ImageIO.framework/Versions/A/ImageIO Expected in: /Users/t/Science/local/lib/libPng.dylib in /System/Library/Frameworks/ImageIO.framework/Versions/A/ImageIO make: error: unable to locate xcodebuild

问题 import pygame works fine for me, but import pygame.font fails with the error: ImportError: dlopen(/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pygame/font.so, 2): Library not loaded: /usr/local/lib/libpng15.15.dylib Referenced from: /usr/local/lib/libfreetype.6.dylib Reason: Incompatible library version: libfreetype.6.dylib requires version 30.0.0 or later, but libpng15.15.dylib provides version 20.0.0 This is in Python 2.7 (not the system version), Mac OS 10

问题 I'm trying to read a png file using libpng 1.2.10 in vs2013. I downloaded the latest zlib and compiled pnglib, which worked fine. Now I'm trying to load a file: int *w = &width; int *h = &height; const char* name = file.c_str(); FILE *png_file = fopen(name, "rb"); if (!png_file) { std::cerr << "Could not open " + file << std::endl; return; } unsigned char header[PNG_SIG_BYTES]; fread(header, 1, PNG_SIG_BYTES, png_file); if (png_sig_cmp(header, 0, PNG_SIG_BYTES)) { std::cerr << "PNG signature

问题 When loading libpng.dll dynamically, after upgrading from libpng13.dll to version 1.5, the compiler started reporting this unresolved external: png_set_longjmp_fn How come and how do I fix it? 回答1: The library was changed to hide internal structures better. So what you need to do is this: typedef jmp_buf* (*png_set_longjmp_fnPtr)(png_structp png_ptr, png_longjmp_ptr longjmp_fn, size_t jmp_buf_size); png_set_longjmp_fnPtr mypng_set_longjmp_fnPtr = 0; Then when you dynamically do a LoadLibrary,

问题 I always get this error when trying to compile my file with Boost::GIL PNG IO support: (I'm running Mac OS X Leopard and Boost 1.42, LibPNG 1.4) /usr/local/include/boost/gil/extension/io/png_io_private.hpp: In member function 'void boost::gil::detail::png_reader::init()': /usr/local/include/boost/gil/extension/io/png_io_private.hpp:155: error: 'png_infopp_NULL' was not declared in this scope /usr/local/include/boost/gil/extension/io/png_io_private.hpp:160: error: 'png_infopp_NULL' was not

问题 I'm trying to write (using libpng) an 16-bit grayscale image where each point color equals to sum of its coordinates. The following code should produce a 16-bit PNG, but instead produces 8-bit like this. Why? #include <stdio.h> #include <stdlib.h> #include <stdint.h> #include <png.h> void save_png(FILE* fp, long int size) { png_structp png_ptr = NULL; png_infop info_ptr = NULL; size_t x, y; png_bytepp row_pointers; png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL); if

问题 I am trying to build the R package png, the repo says that libpng needs to be available. I run a Linux Fedora 20 distro Looks like I have it... [root@localhost bin]# yum install libpng Loaded plugins: langpacks, refresh-packagekit Package 2:libpng-1.6.3-3.fc20.x86_64 already installed and latest version Nothing to do But when I try to install it: > install.packages("png") Installing package into ‘/home/statquant/R/x86_64-redhat-linux-gnu-library/3.0’ (as ‘lib’ is unspecified) trying URL 'http

问题 I've searched a lot of topics about linking libpng to my android ndk project but I've found right answer for my problem and I hope somebody will help me. This is hierarchy of my project: jni different_cpp_files different_hpp_files Android.mk libpng different_cpp_files different_hpp_files Android.mk Android.mk in libpng folder: LOCAL_PATH:= $(call my-dir) include $(CLEAR_VARS) LS_C=$(subst $(1)/,,$(wildcard $(1)/*.c)) LOCAL_MODULE := png LOCAL_SRC_FILES := \ $(filter-out example.c pngtest.c,$

问题 I'm trying to use libpng to split an image into different chunks. The reason being I can't load a texture larger than 512x512 on the hardware I'm working on currently. I accomplished this before with a mixture of SDL and SDL_Image. I basically used the srcrect argument in SDL_BlitSurface to copy just a portion of the image which I then converted into a OpenGL texture. Combine that with a simple loop horizontally then vertically I was able to get an array of textures each a max of 512x512.