Image compression using the DCT method
Image compression is used to reduce the size of a digital image file. This is necessary to boost speeds across the internet, as clients can download the compressed image and encode it on their device instead of downloading the larger file. That way, they can view the highest quality version of the image. One of the methods by which these images are compressed is through a process called DCT Compression, which we’ll be going over in this glossary.
What is DCT Compression and How Does It Work?
Discrete Cosine Transform (DCT) compression reduces redundancy in an image, specifically with the JPEG format. The image is split into 8×8 or 16×16 blocks, then run through an algorithm to quantify, encode, and transmit. On the receiving end, the blocks are decoded, an algorithm is run for the inverse of the original, and then the blocks are re-assembled.
Without getting into the complexities of mathematical algorithms, DCT compression has become the de-facto standard for JPEG images. It’s consistently reliable and can factor in dimensional information (like spatial or temporal). This makes it the preferred option over other compression algorithms.
Image Compression with Cloudinary
Image compression is an important factor when planning to deliver media. And with Cloudinary’s media optimization, we automatically compress images using the optimal encoder for the task. Our API can encode JPEG images automatically through f_auto, including with DCT compression.
If you want to get a headstart on optimizing your media, try Cloudinary today. You can sign up for free today!
