C/C++的PNG图片编码和解码库:LodePNG

jopen 10年前

LodePNG是一个 PNG 格式图片的编码和解码库,尽在其中,没有任何依赖和联动zlib或libpng的要求。
它专为C(ISO C90)开发,并且具有一个C++封装,提供更方便的接口。

/*  LodePNG Examples     Copyright (c) 2005-2012 Lode Vandevenne     This software is provided 'as-is', without any express or implied  warranty. In no event will the authors be held liable for any damages  arising from the use of this software.     Permission is granted to anyone to use this software for any purpose,  including commercial applications, and to alter it and redistribute it  freely, subject to the following restrictions:         1. The origin of this software must not be misrepresented; you must not      claim that you wrote the original software. If you use this software      in a product, an acknowledgment in the product documentation would be      appreciated but is not required.         2. Altered source versions must be plainly marked as such, and must not be      misrepresented as being the original software.         3. This notice may not be removed or altered from any source      distribution.  */     #include "lodepng.h"  #include <iostream>     /*  3 ways to decode a PNG from a file to RGBA pixel data (and 2 in-memory ways).  */     //g++ lodepng.cpp example_decode.cpp -ansi -pedantic -Wall -Wextra -O3        //Example 1  //Decode from disk to raw pixels with a single function call  void decodeOneStep(const char* filename)  {    std::vector<unsigned char> image; //the raw pixels    unsigned width, height;       //decode    unsigned error = lodepng::decode(image, width, height, filename);       //if there's an error, display it    if(error) std::cout << "decoder error " << error << ": " << lodepng_error_text(error) << std::endl;       //the pixels are now in the vector "image", 4 bytes per pixel, ordered RGBARGBA..., use it as texture, draw it, ...  }     //Example 2  //Load PNG file from disk to memory first, then decode to raw pixels in memory.  void decodeTwoSteps(const char* filename)  {    std::vector<unsigned char> png;    std::vector<unsigned char> image; //the raw pixels    unsigned width, height;       //load and decode    lodepng::load_file(png, filename);    unsigned error = lodepng::decode(image, width, height, png);       //if there's an error, display it    if(error) std::cout << "decoder error " << error << ": " << lodepng_error_text(error) << std::endl;       //the pixels are now in the vector "image", 4 bytes per pixel, ordered RGBARGBA..., use it as texture, draw it, ...  }     //Example 3  //Load PNG file from disk using a State, normally needed for more advanced usage.  void decodeWithState(const char* filename)  {    std::vector<unsigned char> png;    std::vector<unsigned char> image; //the raw pixels    unsigned width, height;    lodepng::State state; //optionally customize this one       lodepng::load_file(png, filename); //load the image file with given filename    unsigned error = lodepng::decode(image, width, height, state, png);       //if there's an error, display it    if(error) std::cout << "decoder error " << error << ": "<< lodepng_error_text(error) << std::endl;       //the pixels are now in the vector "image", 4 bytes per pixel, ordered RGBARGBA..., use it as texture, draw it, ...    //State state contains extra information about the PNG such as text chunks, ...  }     int main(int argc, char *argv[])  {    const char* filename = argc > 1 ? argv[1] : "test.png";       decodeOneStep(filename);  }

项目主页:http://www.open-open.com/lib/view/home/1415926476289