Qt: pull a section of image data on the fly -

i have large image(10000*10000) , several reasons cannot modify (like chop smaller tiles.)

i don't want display whole image small section of improve gui efficiency. when user click , drag around, new part of image displayed in viewport. so, how pull section of image data on fly?

i don't recall qt providing support working partial images in case of high resolutions. maybe libtiff.

basically, image composed of either strips or tiles, can use tiffreadscanline() or tiffreadencodedstrip() respectively load portions of image. can compose image appropriate resolution viewport.

alternatively, take @ qtiffhandler class, private class in qt not directly accessible, copy , if necessary modify source expose functionality. internally uses libtiff well.