On entry, buf_size is the size of the output buffer pointed at by pBuf, which should be at least ~1024 bytes. bool compress_image_to_jpeg_file( const char *pFilename, int width, int height, int num_channels,Ĭonst uint8 *pImage_data, const params &comp_params = params()) num_channels must be 1 (Y), 3 (RGB), or 4 (RGBA), image pitch must be width*num_channels. Include jpge.h and call one of these helper functions in the "jpge" namespace: Thanks to Alex Evans for adding several features to jpge (see a smaller jpg encoder). The source distribution includes a sample VS2019 Win32/圆4 solution and CMakeLists.txt file for compilation with gcc/clang. This property makes the decompressor useful on small 32-bit microcontrollers. Also unlike many other small JPEG decompressors, jpgd.cpp does not require loading the entire image into memory, just single MCU rows at a time (even when doing linear chroma upsampling). Unlike every other small JPEG decompressor I've seen, this decompressor has been fuzz tested using zzuf and afl, making it resilent against crashing, overwriting memory, or bad memory reads when given accidently or purposely corrupted inputs. It supports both box and linear chroma upsampling, and grayscale or H1V1/H2V1/H1V2/H2V2 chroma upsampling factors. The source distribution also includes an optional, completely stand-alone public domain (or Apache 2.0) JPEG decompression class with progressive image support in a single source file jpgd.cpp. The current release supports both single pass Huffman coding and more efficient (but slower) two pass coding, makes only a single dynamic memory allocation, and now accepts 32-bit source images. The core compression class consists of a single 890 line C++ file with a small header, along with a couple optional higher-level helper/example functions. It supports grayscale and H1V1/H2V1/H2V2 chroma subsampling factors, Libjpeg-compatible quality settings, and is reasonably fast with fairly low (typically less than 64KB) memory consumption. Choose "Save As" from the "File" menu, and select JPEG as the file format to save the compressed JPEG file.A small (~1000 lines), easy to use public domain (or Apache 2.0) C++ class in a single source file jpge.cpp that writes baseline JPEG compressed images.Lower values result in more compression and a smaller file size. Enter a lower value for the "Horizontal" and "Vertical" fields.In the "Resize and Skew" window, make sure the "Maintain aspect ratio" option is selected. Windows users can use the built-in image editor app called Paint to compress JPEG files. Click "Save" to save the compressed JPEG file.Lower quality values result in more compression and a smaller file size. In the "Export As" window, select JPEG as the format, and adjust the quality slider to a lower value.Mac users can use the built-in Preview app to compress JPEG files. The tool will create a compressed JPEG file that you can download to your computer.Click the "Compress Image" button to compress the JPEG file.Once the file is uploaded, you can adjust the compression settings to reduce the file size.Click the "Choose File" button to upload your JPEG file.You can compress a JPEG file using this online image compression tool. It involves color space transformation, discrete cosine transform, quantization, and entropy coding. JPEG compression reduces image file size by removing redundant information using lossy compression.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |