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The lazy and simply JPEG encoder + JPEG decoder implementation. This project is not for practical because it was implemented for learning.
- GCC 7.1.0 or later (Has not operation check, but this would probably work in the Clang version 4.0.0 or later,too.)
- Boost C++ Libraries
- Srook C++ Libraries
- Supported inputing file format is PNM(Portable anymap) P3(portable pixmap format) only. If You can use the ImageMagick, can convert as like bellow.
$ convert -compress none <input image file> <output.ppm>
- Huffman codes and quantization tables are fixed (Reference: ISO/IEC 10918-1 ITU-T 81 Annex K)
- JFIF version 1.02
- The sampling rate is fixed to 2 : 1
- The restart interval is unabled
- The thumbnail is unabled
- Even if it is a gray scale image, this tool will use component that Cb and Cr
The following is an example of the result that compressed The Standart Test Images of Lena.
$ convert -compress none lena512color.tiff lena.ppm
$ ./jpezy_encode lena.ppm lena.jpg
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|__/|_| |___/ by roki
Reading the input file... width: 512 height: 512
Done! Processing time: 0.522(sec)
Start encoding and writing ...
Write JPEG Header ... Done! Processing time: 0(sec)
Encoding ... Done! Processing time: 0.042(sec)
Write EOI ... Done! Processing time: 0(sec)
Output size: 18010 byte
Done! Processing time: 0.045(sec)
Total processing time: 0.567
$ file lena.jpg
output.jpg: JPEG image data, JFIF standard 1.02, resolution (DPI), density 96x96, segment length 16, comment: "Encoded by jpezy", baseline, precision 8, 512x512, frames 3
The following is an example of the result that compressed The Standart Test Images of Lena.
$ ./jpezy_decode lena.jpg output.ppm
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_/ | .__/ \___/___|\__, |
|__/|_| |___/ by roki
process started...
Loaded JPEG: 512x512, presicion 8, "Encoded by jpezy", JFIF standart 1.02, dots inch, frames 3, density 96x96
Done! Processing time: 0.055(sec)
Decoded image: Netpbm image data, size = 512 x 512, pixmap, ASCII text
$ file output.ppm
output.ppm: Netpbm image data, size = 512 x 512, pixmap, ASCII text
$ ./jpezy_decode lena.jpg output.ppm -v
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|__/|_| |___/ by roki
process started...
analyzing header...
found marker: [APP0]
analyzing jfif... Done! Processing time: 0(sec)
found marker: [COM]
found marker: [DQT]
analyzing DQT... Done! Processing time: 0(sec)
found marker: [DQT]
analyzing DQT... Done! Processing time: 0(sec)
found marker: [DHT]
analyzing DHT... size: 12
found DC Huffman Table... Done! Processing time: 0(sec)
found marker: [DHT]
analyzing DHT... size: 12
found DC Huffman Table... Done! Processing time: 0(sec)
found marker: [DHT]
analyzing DHT... size: 162
found AC Huffman Table... Done! Processing time: 0(sec)
found marker: [DHT]
analyzing DHT... size: 162
found AC Huffman Table... Done! Processing time: 0(sec)
found marker: [SOF0]
analyzing frames... VSize: 512 HSize: 512 Done! Processing time: 0(sec)
found marker: [SOS]
analyzing scan data... Done! Processing time: 0(sec)
Done! Processing time: 0(sec)
Loaded JPEG: 512x512, presicion 8, "Encoded by jpezy", JFIF standart 1.02, dots inch, frames 3, density 96x96
decoding started... Done! Processing time: 0.052(sec)
Done! Processing time: 0.052(sec)
Decoded image: Netpbm image data, size = 512 x 512, pixmap, ASCII text
$ git clone https://github.com/falgon/jpezy.git
$ cd jpezy
$ mkdir build && cd build
$ cmake -DCMAKE_BUILD_TYPE=Release ..
$ make -j$(nproc)or with Ninja
$ git clone https://github.com/falgon/jpezy.git
$ cd jpezy
$ mkdir build && cd build
$ cmake -G Ninja -DCMAKE_BUILD_TYPE=Release ..
$ ninjaUsage: jpezy_encoder <input.ppm> ( <ouput.(jpeg | jpg) [OPT: --gray]> | <output.ppm> | --debug )- input.ppm: Input ppm image file
- output.(jpeg | jpg) [OPT: --gray]: Output jpeg or jpg image. When you designate the
--grayoption, the image is output in gray scale. - output.ppm: When you designate ppm, the image is output ppm without doing anything.
- --debug: When you designate this option, the image is not output, and ppm data are just output on standard output.
Usage: jpezy_decoder <input.(jpg | jpeg)> ( <output.ppm | [OPT: --gray]> | -v )- input.(jpg | jpeg): Input JPEG image file
- output.ppm: Output ppm image file
- --gray: Image is output in gray scale.
- -v: Verbose mode.
The examples using decoder as a library are as follows.
#include"jpezy_decoder.hpp"
#include"decode_io.hpp"
int main()
{
jpezy::decoder<jpezy::Release> dec("input.jpg"); // appoint the input JPEG image file
const auto raw = dec.decode<jpezy::COLOR_MODE>(); // Decoding and returning rgb raw data. This value wrapped optional.
if (!raw) return EXIT_FAILURE;
const auto& [r, g, b] = raw.value(); // getting rgb data by structure bindings.
std::ofstream ofs("output.ppm"); // appoint the output PPM image file.
jpezy::decode_io decio(dec.pr.get<jpezy::property::At::HSize>(), dec.pr.get<jpezy::property::At::VSize>(), r, g, b); // passing data to helper that jpezy::decode_io
ofs << decio; // Outputing the PPM file.
}