Comments on: Extracting image binary info without loading the entire file

By: Hadi Tavakoli

Hadi Tavakoli — Wed, 06 Jul 2011 16:16:36 +0000

Mike, I’ve been recently built a newer class which does a better job than this class… maybe I post a blog about that on the weekend…

Hadi

By: mike

mike — Wed, 06 Jul 2011 15:18:54 +0000

Please help, how to correctly use this in iteration

this code don’t work:
for (var i:Number = 0; i < my_total; i++) {
var thumb_url = my_images[i].@MIN;
var myExtractor:ImageInfoExtractor = new ImageInfoExtractor();
myExtractor.addEventListener(ImageInfoExtractor.PARSE_COMPLETE, infoHandler);
myExtractor.addEventListener(ImageInfoExtractor.PARSE_FAILED, errorHandler);
myExtractor.file = thumb_url;
function infoHandler(e:Event):void {
var line1:String = "W: " + myExtractor.width;
var line2:String = " x H: " + myExtractor.height;
trace( line1 + line2 );
}
function errorHandler(e:Event):void {
trace( "Size could not be obtained, file was not according to JFIF specification" );
}
}

Results:
W: 0 x H: 0
W: 0 x H: 0
W: 0 x H: 0
W: 126 x H: 90

only last img is correct

any suggestions?

By: Hadi Tavakoli

Hadi Tavakoli — Sun, 29 May 2011 14:31:51 +0000

jpges must be well formated, try to save your jpg files using the “save for web” option in photoshop!

By: Joost

Joost — Sun, 17 Apr 2011 12:45:37 +0000

I’m running into problems. For some reason, it doesn’t seem to work with all JPG’s. When I pull a random JPG off the internet, it seems to work (at least 4/4 tries worked) but I have a few jpg’s that fail as well

Error: Error #2030: End of file was encountered.
at flash.utils::ByteArray/readBytes()
at com.myflashlab.classes.tools.imageEncoders::ImageInfoExtractor/::read()
at com.myflashlab.classes.tools.imageEncoders::ImageInfoExtractor/::checkJPG()
at com.myflashlab.classes.tools.imageEncoders::ImageInfoExtractor/::checkType()
at com.myflashlab.classes.tools.imageEncoders::ImageInfoExtractor/::onImageProgress()

By: Andrei

Andrei — Wed, 24 Nov 2010 22:02:05 +0000

Ok, I got it working. Ping me if you need a code sample.

By: Andrei

Andrei — Wed, 24 Nov 2010 17:22:49 +0000

Have you tried extracting “PLTE” chunk? Here is PNG specification http://www.libpng.org/pub/png/spec/1.2/PNG-Chunks.html

By: Garnet Afshari

Garnet Afshari — Tue, 09 Nov 2010 12:08:37 +0000

I am really liking this website except I am having some issues with getting the rss feed to show up in Google Chrome. Any suggestions? Thank you much!

By: Hadi Tavakoli

Hadi Tavakoli — Wed, 01 Sep 2010 10:45:02 +0000

seems like you have already got the answer, but anyhow, in my sample, I actually try loading the file with URLLoader and check if we have enough binary info to read the header of the file… when we do, I kill the loading process which is usually less than 5k.

By: Pierre Chamberlain

Pierre Chamberlain — Tue, 31 Aug 2010 17:02:52 +0000

Hey I’m trying to do something similar but with auto-generated ZIP files.

How were you able to read the filesize prior to the loading? Are you making two consecutive calls? (One to determine the size, another one to get the actual file(s))

To further understand what I’m trying to achieve, please see this thread on Ultrashock:
http://www.ultrashock.com/forums/data-communication/as3-urlstream-php-zip-on-demand-get-bytestotal-filename-126242.html

I’m curious as to how you did it. Everywhere I’m reading, it seems a standalone / browser SWF object cannot get httpResponseStatus events, but in AIR it can.

Any help would be great! Thanks

By: Hadi Tavakoli

Hadi Tavakoli — Tue, 09 Jun 2009 22:29:03 +0000

@Aaron, well, the main part is to know what information you are looking for in the binary loaded data… I think searching the web for the exif info would help to know what is to be found for your special purposes and then you may do anything with it…

I am also trying to find a way to extract the inner thumbnail being available in jpeg files so I can load an image thumbnail without having to manually create a thumbnail!!! Working with binary data is really fun and a lot of new things are possible.

If you found some new interesting things, let us know about it also here