JPEG QUANTIZATION TABLE ESTIMATION WITH CONTROLLED FALSE DETECTIONS
by Rafael Grompone von Gioi grompone@gmail.com
and Tina Nikoukhah tina.nikoukhah@gmail.com
This program implements an a-contrario estimator of the JPEG quantization table.
The following libraries are required for image input/output:
- libpng
- LibTIFF
- libjpeg
-
src/jpeg_qt.c and src/jpeg_qt.h: JPEG Q-table estimation algorithm.
-
src/main.c: Main code: command line interface.
-
README.md: this file.
-
LICENSE: GNU AFFERO GENERAL PUBLIC LICENSE Version 3.
-
Makefile: Compilation instructions.
-
src/iio.c and src/iio.h: iio code and header.
-
*.{png,jpg}: Test images.
The compiling instruction is
makefrom the directory where the Makefile is located.
To verify a correct compilation you can apply the algorithm on the test images 'roma.png' and 'roma95.jpg'. This can be done by executing:
make testThis should print the following message:
test on roma.png
================
./jpeg_qt roma.png
estimated quantization matrix (- when not meaningful):
- - - - - - -
- - - - - - - -
- - - - - - - -
- - - - - - - -
- - - - - - - -
- - - - - - - -
- - - - - - - -
- - - - - - - -
associated log10(NFA) values:
5.9 6.0 5.8 6.0 5.1 5.5 5.4
5.9 6.0 6.0 6.0 6.0 6.0 6.0 6.0
5.9 6.0 6.0 6.0 5.8 6.0 6.0 6.0
5.9 6.0 5.7 6.0 6.0 6.0 6.0 6.0
5.9 6.0 6.0 5.9 6.0 6.0 5.7 6.0
5.7 6.0 6.0 6.0 5.7 6.0 6.0 6.0
6.0 6.0 6.0 6.0 6.0 5.8 6.0 6.0
6.0 5.7 6.0 5.4 6.0 5.5 6.0 6.0
test on roma95.jpg
==================
./jpeg_qt roma95.jpg
estimated quantization matrix (- when not meaningful):
1 1 2 2 4 5 6
1 1 1 2 3 6 6 6
1 1 2 2 4 6 7 6
1 2 2 3 5 9 8 6
2 2 4 6 7 11 10 8
2 4 6 6 8 10 11 9
5 6 8 9 10 12 12 10
7 9 10 10 11 10 10 10
associated log10(NFA) values:
-15.8 -12.4 -636.0 -604.6 -845.0 -592.9 -400.0
-13.5 -15.6 -10.8 -560.8 -793.6 -627.5 -453.6 -301.6
-13.8 -12.1 -600.5 -536.3 -756.2 -537.6 -320.4 -270.3
-14.9 -647.4 -574.6 -755.5 -623.2 -305.3 -212.7 -192.0
-678.5 -595.5 -847.6 -630.5 -421.2 -174.1 -124.8 -94.4
-600.6 -904.6 -675.5 -491.2 -274.8 -128.3 -59.8 -44.0
-927.5 -664.1 -435.4 -227.0 -134.7 -42.1 -25.2 -22.4
-627.5 -386.7 -241.3 -143.6 -69.2 -42.7 -14.4 -2.2The program is executed as:
jpeg_qt(use ./jpeg_qt if the command is not included in the current path). That should print the following usage:
error: usage: jpeg_qt <image>
The command takes an input image as argument. Any image file format handled by Enric Meinhardt-Llopis' IIO library can be used. This includes, for example, PNG, JPG, TIFF, PPM, PGM.
A typical execution is as follows:
./jpeg_qt roma.png
Copyright (c) 2020-2022 Rafael Grompone von Gioi grompone@gmail.com
Copyright (c) 2020-2022 Tina Nikoukhah tina.nikoukhah@gmail.com
JPEGQ is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
JPEGQ is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GGNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License along with this program. If not, see https://www.gnu.org/licenses/.
We would be grateful to receive any comment, especially about errors, bugs, or strange results.