It’s also the most misunderstood.
Here are some common misconceptions and facts.
It’s an acronym forJoint Photographic Experts Group, the organization that developed the format.
Saving an image repeatedly during the same editing session without ever closing the image willnotaccumulate a loss in quality.
Minimize the number of editing sessions between the initial and final version of a JPEG image.
Repeated savingwithin the same editing sessionwon’t introduce additional damage.
It only happens when the image is closed, re-opened, edited, and saved again.
The same setting rule just explained doesn’t apply whencroppinga JPEG, however.
Compression is applied in small blocks, typically 8- or 16-pixel increments.
Some software offers a lossless cropping feature for JPEGs, such as the freeware JPEGCrops.
Some software and digital cameras use terminology likelow,mediumandhighfor quality tweaks.
A progressive JPEG is larger in file size and requires more processing power to decode and display.
This slight delay is barely noticeable, except perhaps on extremely slow systems.
Always keep a lossless primary copy of any image you expect to edit again in the future.
This mimicry works best when the background is a subtle texture where seams are indistinguishable.
JPEG images are ideal for large photographic images with millions of colors.
GIFs are ideal for images with sharp lines and large areas of a single color.
Converting a typical GIF image to JPEG will result in color shifting, blurring, and loss in quality.
The resulting file will often be larger.
An image must have at least 480 x 720 pixels for an average quality print of a 4-by-6-inch photo.
It must have 960 x 1440 pixels or even more for a medium- to high-quality print.
