PUBLIC MARKS with tag png

Compress PNG, JPEG, and GIF images

PunyPNG is a free website optimization tool that dramatically

reduces the file size of your images without any loss of quality.

For this project, I have a page template with several container elements that all have a 1 pixel by 1 pixel PNG background set to repeat, and it looks great when testing it in IE 7 and IE 8. So, I created my next page template with the same styling. This time, IE 7 and 8 both choked when handling the background-repeat. Instead of repeating, both of these browsers inexplicably tried to stretch the 1×1 image across the entire container. The PNG happened to have 60 percent alpha transparency, but I’m not sure that matters. A coworker suggested making it a 10×10 pixel image instead, just to see what happens. Surprise, surprise. That fixed it.

using an HTML5 canvas element and then inserted into the DOM. The results look the same as using a normal 24-bit PNG but are one-half to one-sixth the size. In one case we got a 573KB 24-bit PNG down to a 49KB JPEG with a 4KB PNG alpha-mask!

The trick is that PNG files are an easy to read, even from high level scripting languages like Python. So you can use the App Engine Image Manipulation Service to convert an image into a smallish PNG, then read the raw data using a pure python library like pypng:

storing JavaScript and CSS in PNG files