JPEG or JPG is a popular, extremely portable image file format used widely by photographers and online. Its delicate balance between portability and quality gives users the best of two worlds – a small file size to store more images and satisfying image quality.
But what is JPEG compression, and how much can you compress a JPG? In this article, we'll answer your questions, including why to compress JPEG files and how to go about it.
JPEG or JPG compression is the act of reducing the size of a JPEG image file. While other image formats feature lossless compression, meaning that the picture loses no quality with compression, JPG features lossy compression, which does.
Lossy compression reduces the image quality as the file size gets smaller. The most obvious thing to happen when a JPEG compresses severely is that finer details disappear. The picture’s pixels get much larger, giving the image a "blocky" appearance.
On the other hand, a small amount of compression will have few artifacts, barely noticeable in busier images with many colors.
JPG files can compress considerably to generate tiny file sizes. But as the image quality gets extremely poor with significant compression, it’s best to balance the amount of compression with image quality. Because with image compression, you ultimately want as little perceptible image quality loss as possible.
The best compression ratio to retain image quality is 10:1. If you're looking to reduce the file size of your photographs while keeping image quality, this is the maximum compression ratio you want to shoot for.
But, if you're feeling adventurous or have extreme compressional needs – you can reduce file sizes to as much as 5% of its original file size. By that point, however, the image quality is so poor that you can’t see what the image represents anymore.
Why compress JPEGs? The main reason to compress JPG images is to reduce file size to save space on your hard drive or portable storage device.
Compressing JPEGs is also desirable when transferring or uploading files online, for the simple reason that smaller files transfer or upload faster.
JPEG is also a great image format for websites because smaller images load faster. Note, however, that images in JPEG format work best for photos with a lot of detail. The JPEG artifacts are more visible on graphics, logos, and clear pictures with text.
Most image processing software, like PaintShop Pro, can do standard lossy JPG compression. When saving an image as JPEG in PaintShop Pro, you get a JPEG Options window. This window lets you adjust image quality from low (small file) to maximum (large file). You can also compress JPEG files in image editing software such as Corel PHOTO-PAINT or with online tools.
The best method that reduces file size but leaves image quality intact is by utilizing a compression software like WinZip. Zip your JPEG files and enjoy a smaller, more convenient space-saving way to store and send photos.
JPEG files continue to be the leading file format for images. With some drawbacks, like visible artifacts with heavy JPEG compression, it’s still an extremely lightweight format that satisfies global viewers both offline and online.