The project consists in a JPEG encoder and decoder 📷.
The encoder does the following:
- Reads a PPM-3 format image
- Divides the image into 8x8 pixels blocks
- DCT (Discrete Cosine Transform) on the 8X8 pixels blocks
- Quantization on the 8X8 pixels blocks
- Entropy Encoding (only ZigZag parsing and run-length encoding, NOT Huffman encoding)
The decoder does the oposite steps of the encoder in reversed order (Entropy Decoding, inverse Quantization, etc.).
The JPEG image is kept only in memory during the program execution. At the end, a PPM-3 image is saved as a result of the decoding. The result image clearly shows how the quality of an image deteriorates when using JPEG.
Before (left) and after (right) the encoding & decoding process.
Open a terminal inside the src folder and just execute the following command:
python main.py
The decoded image will be saved in /res/images/processing/decoded_rgb.ppm.
In order to change the image to be processed, change the file_name variable inside src/main.py (line 3) to the path which is pointing to the desired image.
More details regarding the project can be found here.
The project was developed with Python ❤️.