GFLAx JPEG2000 Request

Discussions on GFL SDK, the graphic library for reading and writing graphic files

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b.e.wilson
Posts: 26
Joined: Wed Mar 09, 2005 7:44 pm

GFLAx JPEG2000 Request

Post by b.e.wilson »

I've been woking on a website that uses many large images, and displays parts of them (for example, see http://herbarium.uvsc.edu/virtual/viewe ... 8218s1.jpg - click on the big image to zoom in)

There is a problem. It takes a couple seconds to open and decompress these images before I can start manipulating them. A couple seconds isn't too bad, but this application will not scale well when lots of traffic arrive. These images are 128 MB uncompressed, and several users can consume a lot of server RAM.

I'd like to switch to jpeg2000 files and use its selective decompress function. The best implementation of this is the j2k-codec.com .dll ($99 US). That codec can open the image without decompressing it, get information on the pixel size and tile size, allow me to select which tiles I want to decompress, then decompress only those.

I wonder if similar functionality can be added to the GFLAx ActiveX component? No, it would give me no speed advantage when the entire image is being viewed (it might be slower, depending on how fast j2p is relative to jpg), but it sure would be faster when viewing only a portion of the image.

Thanks,

Bruce
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xnview
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Joined: Mon Oct 13, 2003 7:31 am
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Re: GFLAx JPEG2000 Request

Post by xnview »

b.e.wilson wrote:I've been woking on a website that uses many large images, and displays parts of them (for example, see http://herbarium.uvsc.edu/virtual/viewe ... 8218s1.jpg - click on the big image to zoom in)

There is a problem. It takes a couple seconds to open and decompress these images before I can start manipulating them. A couple seconds isn't too bad, but this application will not scale well when lots of traffic arrive. These images are 128 MB uncompressed, and several users can consume a lot of server RAM.

I'd like to switch to jpeg2000 files and use its selective decompress function. The best implementation of this is the j2k-codec.com .dll ($99 US). That codec can open the image without decompressing it, get information on the pixel size and tile size, allow me to select which tiles I want to decompress, then decompress only those.

I wonder if similar functionality can be added to the GFLAx ActiveX component? No, it would give me no speed advantage when the entire image is being viewed (it might be slower, depending on how fast j2p is relative to jpg), but it sure would be faster when viewing only a portion of the image.
Currently not possible, GFLAx load the full picture.
Pierre.