libjpeg

问题 I want to install PIL package on windows, its easy. but decoder jpeg not available. which packages are needed to download and installed befor PIL so it gets work? 回答1: I found the solution. one has to use easy_install PIL instead of pip install PIP in Windows. easy_install finds local installation or installs the libjpeg from the source and connects it to PIL while pip cannot do that. 回答2: Solution that worked for me (assuming you have the tools to compile packages, which depend on your

问题 Edit: im now using http://code.google.com/p/jpeg-compressor/ so i dont care about making this work anymore. I downloaded the http://ijg.org/ source code, i tried to build it as a DLL file. This is farthest i could build until i went into dead-end. I noticed there was some .c files which i had to delete, but i dont know if i deleted the correct ones, there was at least these files jmemmac.c and jmemdos.c which i figured i dont need. I had to delete jmemmac.c because i compile on windows, but

问题 Edit: im now using http://code.google.com/p/jpeg-compressor/ so i dont care about making this work anymore. I downloaded the http://ijg.org/ source code, i tried to build it as a DLL file. This is farthest i could build until i went into dead-end. I noticed there was some .c files which i had to delete, but i dont know if i deleted the correct ones, there was at least these files jmemmac.c and jmemdos.c which i figured i dont need. I had to delete jmemmac.c because i compile on windows, but

问题 I am starring at the original JPEG standard (ITU 81), in particular the figure Figure F.12: extending the sign bit of a decoded value in V : For reference the SLL terms means: shift left logical operation (see page 15 of the PDF) Now the famous libjpeg implementation decided to implement it this way (quite direct transcription): /* * Figure F.12: extend sign bit. * On some machines, a shift and add will be faster than a table lookup. */ #ifdef AVOID_TABLES #define HUFF_EXTEND(x,s) ((x) < (1<<

问题 I'm using libjpeg right now to save JPEG images. If there is an error, libjpeg's default behavior is to call exit() , which I want to avoid since it's not a fatal error for my program. libjpeg allows you to use your own error manager, and mandates that if you use your own error_exit() function (which calls exit() by default) you must not return control to the caller. libjpeg suggests using setjmp.h to meet this requirement and not exit() the program. However, I am writing a C++ program, and I

问题 my problem is fairly simple.. I'm not able to link libjpeg-turbo in my project. I'm looking to try this exemple, but i'm not able to compile : I'm not sure what i'm doing wrong : 回答1: You can download vcpkg from github and run vcpkg.exe in the Powershell prompt( opened in administrative mode) . vcpkg can install many open source projects (both static and dynamic libraries are supported) as packages ready for use in VS 2017 and VS 2015 (SP3) IDE. You can use choose x86 or x64 platform and in

问题 I need to decode (unpack into bitmap) pretty small (about 1200 * 1200) JPEG. The problem is I need to do it quickly. I have tried libjpeg, and it's quite slow. I have also tried BitmapFactory.decodeByteArray - it's a bit faster, but still not fast enough. What are another options? A native (C++) library is much preferred. P.S. My JPEGs are created directly in memory. P.P.S. I wonder how come libjpeg is slower than BitmapFactory.decodeByteArray. 回答1: Try Libjpeg Turbo: http://libjpeg-turbo

问题 I need to decode (unpack into bitmap) pretty small (about 1200 * 1200) JPEG. The problem is I need to do it quickly. I have tried libjpeg, and it's quite slow. I have also tried BitmapFactory.decodeByteArray - it's a bit faster, but still not fast enough. What are another options? A native (C++) library is much preferred. P.S. My JPEGs are created directly in memory. P.P.S. I wonder how come libjpeg is slower than BitmapFactory.decodeByteArray. 回答1: Try Libjpeg Turbo: http://libjpeg-turbo

问题 I've got a simple C++ app that decodes JPEGs with libjpeg - however, some of the images it processes come out sideways! These input images have orientations baked in to the EXIF data by the camera, but it seems that during decompression, libjpeg isn't taking the orientation flag into account as many JPEG viewers do. Is there a way to get libjpeg to respect the orientation of the JPEG during decompression, or will I have to parse out this orientation tag and manually rotate the image? 回答1: the