hs2361 / k-means-compressor

k means clustering based image compression algorithm project for OOPL

Image Processing and Compression Library

Overview

This library aims to provide its users with basic image processing operations along with ways to compress the images. Currently the following operations are supported:

1. RGB to Grayscale
2. Horizontal and Vertical Flip

Support for more operations are welcome!

Image Compression

Image compression is done using the k-means algorithm, pixel values are grouped together to form bands of pixels, hence making it more compressable for JPEG and other methods of compression.

Results

How to set up

Note: You need to have GCC version > 10.2.0

1. Clone the repo with git clone https://github.com/DebadityaPal/k-means-compressor
2. Run the software with CLI commands The CLI commands are:

g++ compressor.cpp -o compressor

compressor <args>

Usage

The arguments are listed below

Usage:
Image Compression(-c):
-i: Path to the input image
-o: Path to the output image
-cl: (Optional, default: 64) Number of clusters used for compression 
-n: (Optional) Normalize the image before compression
-it: (Optional, default: 5) Number of epochs for k-means compression

Batch Compression (-b):
-i: Path to the input directory
-o: Path to the output directory
-f: Format for output images
-cl: (Optional, default: 64) Number of clusters used for compression 
-it: (Optional, default: 5) Number of epochs for k-means compression

Seam Carving (-s):
-i: Path to the input image
-o: Path to the output image
-p: (Optional, default: 1) Percentage of width to be retained    
   
Image editing (-e):
-g: Convert to grayscale
-h: Flip the image horizontally
-v: Flip the image vertically
-i: Path to the input image
-o: Path to the output image

k-means-compressor's Issues

[BUG] Every other operation ends with Single image Compression

The CLI code was written in such a way that every operation resulted in k-means compression, the other methods were not being able to be executed at all.

[DOCUMENTATION] Improve Documentation

We would like to have a docstring for each function that explains the function in brief. Check out the various styles for C++ docstrings, contact maintainers to decide on which one to use.

[BUG] Parameter -p in seam carving works in opposite manner

Currently the Usage section of the cli states that the -p parameter in seam carving command is the percentage of width to be reatined but the program instead cuts that much percentage from the image.

Example:
./compressor -s -i input.png -o output.png -p 0.3 will cut 30% rather than retaining 30%.

[FEATURE] Convolution Operation with filter libraries

Create a convolution operation that can take in custom filters and operate on the picture, also manage a default Convolution filter library of commonly used filters that can also be used with the function.

[BUG] Formula for converting image to grayscale is incorrect

The following line converts an image to grayscale by giving equal weights of 0.33 to RBG.

k-means-compressor/python/ImageEdit.py

Line 29 in be96c57

orig_img = np.sum(orig_img*0.33,axis = 2)

Whereas the correct weights should have been [0.3, 0.59, 0.11] for RGB respectively.

[FEATURE] Add Unit Tests

We need unit tests to actively test correctness for new PRs.
A good package to write C++ unit tests is: Google Test
Feel free to take a look at the package and implement a unit test suite for the project.

[FEATURE] Extend support for C++ version < 17

Currently, we don't know the exact reason for this version dependency however, it might be related to the filesystems library in C++ being used by BatchCompressor.hpp
Please help us figure out the reason behind this and help us solve this dependency.
Backwards compatibility is a major issue.

[FEATURE] Cropping function

We need support for cropping of images, implementation should be simple enough as it would involve simply slicing the array.

[DOCUMENTATION] Fixing compilation syntax

The documentation contains -
gcc -std=C++17 compressor.cpp
for compiling the program, this however does not work due to linking issues and hence the documentation needs to be updated.

[FEATURE] Remove bits/stdc++.h

The bits/stdc++.h header file used is a nonstandard header file that might not work with non-GNU compilers like Clang. Hence, we should get rid of it.
Try to import the header dependencies individually and remove all instances of bits/stdc++.h