[Qt-interest] Interested in Tiling large images

[Cole, Derek]

Hello,

I am running into a problem trying to display large commercial imagery in a QGraphicsview/Scene.

Presently, I have been putting my smaller sample images into QGraphicsPixmapItems. This generally requires generating a QImage from the raw byte data,  pixmap from the QImage, and then sticking that pixmap into an item, and putting the item on the scene.

Apparently one of these items has a limit on the size - could someone point me to the max constraints on these images?

I have had no problem with my smaller test images that were about 8192^2 pixels. These test image are about 35000^2.

I am reading the raw data out of a JPEG2000 driver, which is what is actually reading the file.

It seems like I may have to go with some kind of tiling strategy..can anyone point me to how that generally works? I want to be able to view pan the image, zoom in/out, etc etc. I already have code for doing this on those QGraphicsItems.  How do I tell which tiles to load(on the edge of my qgraphicsview I guess?), which to discard(not visible in my qgraphicsview?), how to translate what is on the screen to a position in the physical data file, etc?

Thanks!

Derek
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