JPG Files And Your Logo
Compression while retaining logo image quality. Most of the time
The original name JPEG is an acronym taken from the Joint Photographic Experts Group which created the standard, but has been abbreviated to JPG for file naming consistency. JPGs are the most common image format used on the internet and when e-mailing images and photographs back and forth. It’s not surprising that JPG is also the default format of most photo capture devices and digtial cameras, Using a JPG format when placing your logo on a website or for some other pixel based application is quite acceptable, with some minor caveats.
Unlike a PNG which is ‘lossless’, a JPG is a ‘lossy’ format which means the file size compression rates can be altered, but with differing rates of image degradation or ‘loss’. Higher image compression rates result in smaller file sizes (for faster download) but with more appreciable loss of image quality and integrity with higher rates. With higher image compression, JPG images start to feature ‘abstracts’, clumps of pixels that can appear ‘dirty’ or ‘fuzzy.’ This is particularly true of colors in the red spectrum and in large, solid areas of color, not typical in photographs where it is less likely that these ‘abstracts’ are noticed. Finer detail can be lost with higher compression rates and smooth tonal blends will begin to ‘band.’ A logo is quite different than a photograph, so we need to take a look at the effect of JPG compression as it applies specifically to logo design. We used a logo we developed for Sips Media to create JPG images using various compression rates, as well as a lossless PNG format.
As you can see, the PNG image is superior to all the others, but the JPG images, even with fairly high compression rates, are still quite acceptable for most applications. It is only when we compressed the image by 70% did we begin to see any noticeable image breakdown. Keep in mind that this is an example for this particular design, and your logo may not compress as well, or image degradation may not be noticeable even with maximum compression. If you’ve decided to design your own logo, you’ll need to experiment with compression rates for optimum results. You’ll also have to decide which is more important – download speed of your website, or the integrity of your logo that’s featured on it.
JPGs are natively in the RGB color space, and are intended primarily for viewing on TVs and computer monitors. When converted to CMYK four color process images (with adequate resolution) for traditional offset reproduction, your logo colors may shift dramatically. This is particularly true with special FX (lens flares, glows, etc) that are added to RGB images in software applications like Photoshop and Fireworks (one of the reasons we advise against them). Background image transparency is not available with JPG images, so if you need your logo to sit on various colored backgrounds, better go with a PNG. For more information, visit the design help center for a quick reference guide for all logo formats.