Hi. This is the place on the web full of things to do with me. I'm an actor, writer, film-maker, occasional open source hacker, sometime creator of web curiosities, and very rarely a photographer. I was chief technical officer for tangozebra, now part of DoubleClick (now part of Google), where I was subsequently lead technical architect. My development background goes back to working in assembler and trying to write far too complex things in BBC BASIC. These days I'll knock up new things in PHP, Python or (sometimes) Java. If you need a consultant technologist or technology strategist, I'm available for hire.
I'm passionate about story telling; about physical movement and having fun with what your body is capable of. I strongly believe that being well-connected with your body and your sensuality is essential to living an enjoyable life.
PNG Weirdness
So for my previous entry I had to create an image. Screenshot, paste into Photoshop, save as PNG. Done. Now a thumbnail: save-for-web, 50% scale, PNG. Done.
Erm.
-rw-rw-r-- 1 james james 16K 2008-04-07 13:42 error-message-large.png -rw-rw-r-- 1 james james 33K 2008-04-07 13:43 error-message-thumb.png
Something's not quite right here: the half-sized thumbnail is taking up twice the space.
error-message-large.png: PNG image data, 1001 x 126, 8-bit/color RGB, non-interlaced error-message-thumb.png: PNG image data, 500 x 63, 8-bit/color RGBA, non-interlaced
Okay, so maybe it's the colour space - RGBA is storing more data. Not, you know, twice as much data, but 32 bit rather than 24 bit is going to hurt in some way. So I go back in, resize the image in Photoshop, and save as PNG using the same options as for the large one.
-rw-rw-r-- 1 james james 26K 2008-04-07 13:45 error-message-small.png error-message-small.png: PNG image data, 500 x 63, 8-bit/color RGB, non-interlaced
Okay, so reducing the colour space to 24 bit does what we expect: reduces the filesize by a quarter. It still doesn't explain why the original is so much smaller. Okay, well Photoshop also comes with ImageReady, so perhaps that can help.
| Input | Dimensions | Input size | Optimised size |
|---|---|---|---|
| large | 1001x126 | 16K | 15.29K |
| thumb | 500x63 | 32.1K | 32.12K |
| small | 500x63 | 25.7K | 25.36K |
| large resized | 500x63 | ~4K | 29.04K |
The last row is the interesting one: when resizing in ImageReady, it generates a 4K image... then optimises it to 29K.
For what it's worth, GIMP doesn't do any better. Anyone have any idea what's going on, or is it just pixies?