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Test a JPG for Progressive Rendering
- codezero 12y agoAlso, FYI, most Unix-like systems have a correct 'magic' file so that running the command: file filename.jpg will say whether or not the image is progressive.
- billyhoffman 12y agoPatrick's tool is far more than an boolean "is this a progressive JPEG or not." Comparing it to the "file" utility is a gross underestimate. It takes a JPEG, converts it to a progressive JPEG, and then uses an animation to show you how that image will look loading as a progressive JPEG vs loading as a the original JPEG. You can see, for example, after 0.5 seconds, how does the progressive JPEG look vs. how much of the original JPEG is rendered? This is incredibly powerful and helpful for people focused on frontend web performance Comparing this to "file" is l
- smackfu 12y agoThis is neat, but it sure could use heck of a lot better index page. Here's an example of the output: http://www.patrickmeenan.com/progressive/view.php?img=http%3A%2F%2Fimg.ffffound.com%2Fstatic-data%2Fassets%2F6%2F093a60c633f619af1ab6c8fda8635bf1fa733bb6_m.jpg http://www.patrickmeenan.com/progressive/view.php?img=http%3...
- Alupis 12y agoCan someone explain to a non-graphics person what this means? Seems like it's just demonstrating how the JPG get's displayed on your page while it's still being downloaded?
- danbruc 12y agoThe page just demonstrates that using progressive JPEGs yields a way better user experience than sequential ones. The page essentially turns an image into an animation simulating the loading behavior of both variants next to each other; while the progressive image is almost immediately completely visible (at low resolution) the sequential one builds up slowly from top to bottom.
- thaumasiotes 12y agoWho says it's a better experience? I always think of progressive images as wasting resources by transmitting worthless information (the unintelligibile progressive image) along with the image I want to see. Text in a progressive jpeg tends to be a smear until you have the whole thing anyway.
- danbruc 12y agoI am not completely sure without checking the specification but still pretty confident that progressive JPEGs are not made up of several images at different resolution but just have the low frequency component first. And images with text are neither the common use case for images nor the intended use case for progressive JPEGs.
- thaumasiotes 12y agoThe user experience is not determined by how the technology secretly works. Appearing to do something wrong is a bad thing in and of itself.
- 12y ago
- teddyh 12y agoIs it only me who is annoyed by “JPG”? It’s JPEG. I mean, you don’t write “HTM” files, do you?
- squeaky-clean 12y agoWell... you can write .htm files.
- Gracana 12y agoYeah, aiui it's kind of a holdover from DOS and three-letter file extensions.
- pornel 12y agoIf you want to be pedantic, the image format is actually called JFIF (JPEG File Interchange Format). It's been designed by the JPEG (Joint Photographic Experts Group).
- teddyh 12y agoYes, but the file extension has always been .jpeg.