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    Arithmetic coding is a form of entropy encoding used in lossless data compression. Below is a Python implementation for compressing an image using arithmetic coding.

    Example

    import numpy as np
    from PIL import Image

    class ArithmeticCoding:
    def __init__(self, image_path):
    self.image = Image.open(image_path).convert('L')
    self.width, self.height = self.image.size
    self.pixels = np.array(self.image).flatten()
    self.probabilities = self.calculate_probabilities()

    def calculate_probabilities(self):
    values, counts = np.unique(self.pixels, return_counts=True)
    probabilities = counts / len(self.pixels)
    return dict(zip(values, probabilities))

    def encode(self):
    low, high = 0.0, 1.0
    for pixel in self.pixels:
    range_ = high - low
    high = low + range_ * sum(self.probabilities[val] for val in self.probabilities if val <= pixel)
    low = low + range_ * sum(self.probabilities[val] for val in self.probabilities if val < pixel)
    return (low + high) / 2

    def decode(self, encoded_value):
    decoded_pixels = []
    low, high = 0.0, 1.0
    for _ in range(len(self.pixels)):
    range_ = high - low
    value = next(val for val in self.probabilities if low + range_ * sum(self.probabilities[v] for v in self.probabilities if v <= val) > encoded_value)
    decoded_pixels.append(value)
    high = low + range_ * sum(self.probabilities[val] for val in self.probabilities if val <= value)
    low = low + range_ * sum(self.probabilities[val] for val in self.probabilities if val < value)
    return np.array(decoded_pixels).reshape((self.height, self.width))

    if __name__ == "__main__":
    ac = ArithmeticCoding("image.png")
    encoded_value = ac.encode()
    decoded_image_array = ac.decode(encoded_value)
    decoded_image = Image.fromarray(decoded_image_array.astype('uint8'))
    decoded_image.save("decoded_image.png")
    Gekopieerd.
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  2. Github
    https://github.com › jasgreenspan › arithmetic-codingDit resultaat vertalen

    Image Compression with Arithmetic Coding - GitHub

    We compared the results of the pure arithmetic encoding method and the hybrid encoding model to the pure Exp-Golomb method (order k=2) on 5 different images. Th…
    General Approach

    Goal
    To use arithmetic coding to improve on the DCT quanitzation method of encoding an image.
    Method
    We build a state model of the DC coefficie…

    Implementation details

    Creating the state model and the probablities
    We chose to implement the model in two ways: (1) where the probablity distribution is over the DC coefficients of the entire image and (2) where the probability distrib…

    How to use the code

    The code is divided into four files: main.py, arithmetic_encoding.py, golomb_encoding.py, and utils.py. To run the complete encoding scheme, as well as test the various methods, use the if name == 'main': in main.py: main from main.py. …

  3. ResearchGate
    https://www.researchgate.net › publicationDit resultaat vertalen

    New Image Compression/Decompression Technique …

    16 okt. 2016 · In this paper, the secret text is compressed twice by an Arithmetic coding algorithm, and the resulting secret bits are hidden in the cover pixels of …

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  5. Stack Overflow
    https://stackoverflow.com › questionsDit resultaat vertalen

    what is the best way to deal with a image for compression by …

    5 aug. 2020 · So, honestly, I doubt any text compression algorithms could beat already existing image compression formats. One thing which I think is wrong with your approach is reading the image using …

    Codevoorbeeld

    const fs = require("fs");
    let data = fs.readFileSync('Cat.png', 'binary');
    fs.writeFileSync('Cat_Copy.png', data, 'binary');
  6. GeeksForGeeks
    https://www.geeksforgeeks.org › image-compre…Dit resultaat vertalen

    Image Compression using Huffman Coding

    11 jul. 2025 · Huffman coding is one of the basic compression methods, that have proven useful in image and video compression standards. When applying …

  7. MDPI
    https://www.mdpi.comDit resultaat vertalen

    An Improved Image Compression Algorithm Using 2D …

    25 sep. 2023 · Of late, image compression has become crucial due to the rising need for faster encoding and decoding. To achieve this objective, the present …

  8. rafat.github.io
    https://rafat.github.io › sites › wavebook › app › c…Dit resultaat vertalen

    Image Compression - GitHub Pages

    We take J = 4 J = 4 stage Discrete Wavelet Transform (derived from Db2 wavelets) of the Lena image, choose the largest 1 50 1 50 coefficients while setting the …

  9. ScienceDirect
    https://www.sciencedirect.com › science › article › piiDit resultaat vertalen

    Arithmetic coding for image compression with adaptive weight-context …

    1 aug. 2013 · In this paper, a new binary arithmetic coding strategy with adaptive-weight context classification is introduced to solve the context dilution and context quantization problems for …

  10. Springer
    https://link.springer.com › articleDit resultaat vertalen

    An improved lossless image compression based arithmetic coding …

    30 jul. 2014 · In this paper, we propose a new approach for a block-based lossless image compression using finite mixture models and adaptive arithmetic coding. Conventional arithmetic encoders encode …

  11. Scribd
    https://www.scribd.com › document › Image-Co…Dit resultaat vertalen

    Image Compression-Decompression Technique Using …

    The document describes a new technique for image compression and decompression using arithmetic coding. It divides images into 64x64 pixel …

  12. International Journal of Computer Applications - IJCA
    https://www.ijcaonline.org · PDF bestandDit resultaat vertalen

    Image Compression with Adaptive Arithmetic Coding

    An image compression method using the wavelet transform, zero tree coding and adaptive arithmetic coding has been proposed. Here a novel static zeroth order adaptive arithmetic coder is being …