What are the best methods for decoding image formats and analyzing headers using Python?

How to decode and analyze the structure of several modern image formats, specifically WebP, JPEG XL, HEIF, and AVIF. My goal is to compare their header information with the actual image data to determine which format is more ‘header information heavy’. I’m planning to use Python for this task.

I’m interested in finding a straightforward method to decode these image formats (for the same image) into either HEX or Binary format. This way, I can assess how much of the file is dedicated to image data versus header information. Ideally, I would like to understand the breakdown of the header information in these various file formats.

Up to this point, I’ve managed to open a file in binary mode as shown in my sample code for an AVIF test image. However, I’m uncertain about how to decrypt, read, and comprehend the structure of these files. While I’ve found some resources online for the JPEG format, like an article explaining JPEG decoding, I haven’t found similar resources for WebP, HEIF, and AVIF formats.

Here’s the Python code I’ve been using for the AVIF image:

image = 'test.avif'

with open(image, 'rb') as image_file:
    content = image_file.read()

Now, I’m seeking guidance on how to extract and understand the header information from these images, especially during the compression process.

To analyze and compare the header information of different image formats like WebP, JPEG XL, HEIF, and AVIF, you’ll need to delve into each format’s specific structure. This task involves using Python libraries capable of parsing these formats to access both the header and image data.

For some formats, Python libraries like Pillow are suitable. However, for more specialized formats such as AVIF or HEIF, you might require dedicated libraries, or direct binary data analysis could be necessary. This approach includes reading the file in binary and interpreting the data as per each format’s unique specifications.

Is there a universal library in Python that can process all these formats?

Currently, there isn’t a single Python library that comprehensively covers all these formats, especially newer ones like JPEG XL or AVIF. You will likely need to use a combination of different libraries, such as Pillow for WebP and JPEG, and specialized ones like pyheif for HEIF. For newer formats like AVIF, binary data analysis is probably your best bet, given the limited support in existing Python libraries.

And if you wish to go about interpreting the binary data in line with each format’s specific structure then, interpreting the binary data of these image files requires a solid grasp of each format’s specifications. These specifications outline how header and image data are stored. You can find this information in the official documentation of each image format.

Understanding the structure, such as markers in JPEG, chunks in WebP, or boxes in HEIF and AVIF, is crucial.