Convert JPEG to pixel intensity array

cdherold has asked for the wisdom of the Perl Monks concerning the following question:

Dearest Monks,

I am humbled once again.

I am about to undertake a daunting task ... multiple object identification and decoding within an image (e.g., JPEG). Screwy out of the box programs don't work for my application ... and I wanted to try to do it myself anyways.

First I need to have an two-dimensional array that will contain the row/column pixel intensity data from the image. Just intensity, not color.

How can I do this so that I can call $pixel[20][450] and get the pixel intensity in row 20, column 450 (and for every other pixel in the image)?

Or where should I start?

Chris

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Re: Convert JPEG to pixel intensity array by Joost (Canon) on Oct 30, 2006 at 23:53 UTC
You can probably use GD. See especially the getPixel() and rgb() methods. Depending on what exactly you mean with "intensity" you might need to do some processing with the RGB values. "What should it profit a man, if he should win a flame war, yet lose his cool?"	[reply]
Re: Convert JPEG to pixel intensity array by jhourcle (Prior) on Oct 31, 2006 at 03:32 UTC
You might want to look at PDL (specifically PDL::IO::Pic). A few of the folks that I work with use it or similar software (IDL, GDL) to analyze images.	[reply]
Re: Convert JPEG to pixel intensity array by zentara (Cardinal) on Oct 31, 2006 at 11:58 UTC
See Perl Image Analysis I'm not really a human, but I play one on earth. Cogito ergo sum a bum	[reply]
Re: Convert JPEG to pixel intensity array by merlyn (Sage) on Oct 31, 2006 at 23:11 UTC
See my column Getting Image Colors to Text for one way. -- Randal L. Schwartz, Perl hacker Be sure to read my standard disclaimer if this is a reply.	[reply]