Compressing an image and changing its format is a simple task. Any basic editor should have the necessary tools, and on certain occasions we can significantly reduce its size without sacrificing too much quality. Now, imagine for a moment that we must process hundreds of images to simplify their online distribution. Most editors don't have a batch image compressor, but the open-source tool Caesium is dedicated exclusively to that.
There are excellent formats for image distribution, and others that are optimal for preservation. For example, NASA recently shared the first images from the James Webb Space Telescope, and anyone interested can download a standard 4 or 5 MB PNG… or the original uncompressed 150 MB TIFF.
NASA can afford that, but the rest of the sites managed by mortals cannot. Compressing images is fundamental to reduce bandwidth consumption, speed up page loading, avoid penalties, and save headaches. Processing an isolated image doesn't present major challenges, but if you plan to compress hundreds of images in one session, maybe you'd like to download a copy of Caesium.
How to compress images with Caesium
The program is divided into four sections: the list of images to process, the control panel to adjust compression for the JPEG, PNG, and WEBP formats, and two panels at the bottom that show the original image and the preview of its compressed version (more on this below). Now, a very important detail to highlight about Caesium is that it doesn't work as a converter: what it does is detect the original format of the image, apply the configured compression, and save a new copy (you'll need to assign an alternative destination folder).
Alternatively, we can tell Caesium to change the physical size through the Resize tab. Combining both functions (compression and resizing) should lead to a significant reduction in logical size, but I recommend monitoring its parameters carefully so that the sacrifice in quality isn't too big.
Caesium supports multithreading and puts a lot of pressure on multi-core processors, but you can disable it if you wish. The program is available in portable version; however, I don't fully recommend it at the moment because its latest build suffers a bug that causes the absence of previews. The installer version should work better.
Official site and download: Click here
