Unraveling the JPEG

“Unraveling the JPEG” is a great deep dive into the JPEG image format. This article is about how to decode a JPEG image. In other words, it’s about what it takes to convert the compressed data stored on your computer to the image that appears on the screen. It’s worth learning about not just because …

Exif.js – JavaScript library for reading EXIF image metadata

Following up on yesterdays “Read EXIF thumbnail from JPG image using JavaScript” I stumbled upon Exif.js, a library which reads EXIF meta data – and not just the thumbnail – from JPEG images. Usage is simple: EXIF.getData(imageElement, function() { alert(EXIF.pretty(this)); }); It’s also possible to get single values: EXIF.getData(imageElement, function() { var make = EXIF.getTag(this, …

Read EXIF thumbnail from JPG image using JavaScript

Little demo by @codepo8 which reads the thumbnail out of the EXIF data of an image: The code itself is very simple: it opens a FileReader and seeks for the second occurrence (*) of 0xFF 0xD8 (Start of Image) along with its following 0xFF 0xD9 (End of Image). All bytes in between are the thumbnail …