Originally Posted by
caduel
Originally Posted by
caduel
I think this is on the right track, I tried a quick test case
testing.
setClipRect (QRect(2700,
2700,
2700,
1350));
QImage testimage
=testing.
read();
QImageReader testing("mapping/worldmed.tif","tiff");
testing.setClipRect (QRect(2700,2700,2700,1350));
QImage testimage=testing.read();
mainImage=new QGraphicsPixmapItem(QPixmap::fromImage(testimage));
To copy to clipboard, switch view to plain text mode
When I ran it my 2 gigs of ram was quickly eaten up and then the correct part of the image was displayed and the ram was released. The operation took approximately 15 seconds. This was on my medium sized image, I ended up killing the operation on the larger one.
I do think this shows promise however.
Thank you.
quote
Originally Posted by
nicolas1
implement custom graphicsitem, which open image and take part of image using ImageMagick api.
but imagemagick is not really efficient on large images. try to use gdal with custom graphicsitem
I havent heard of gdal and I will be reading up on it. GDal look interesting for more then just using it for image handling.
Originally Posted by
patrik08
This Month i writteln ready a
QFuture Tifflib an this code can read tiff over 2GB on linux and Max 2GB on window.
QImage having limit size of 32000 pixel
My experience say 9000-12000.
If you like to write selft this piece of code read source from
http://mcmcweb.er.usgs.gov/drc/dlgv32pro/ and search TIFFOverlay and port to QT4.
Otherwise if you like to save 10 day work send me a message.
thank you before I bug you for that I have to decide if it is practical what I am trying to do just do to the amount of data I am dealing with. I am also looking into marble as something to use.
Bookmarks