while input and output images work fine even on bigger sizes,
it was an assumption that users would supply a folder with real small thumbnails as collection param.
If some one passes a directory full of real digicam pics as collection, in most cases it freezes the user's system.
Solution - precalculations based on source dimensions and zoom factor
- warnings when more than a tolerable number of big images are found in thumbnails.
while input and output images work fine even on bigger sizes,
it was an assumption that users would supply a folder with real small thumbnails as collection param.
If some one passes a directory full of real digicam pics as collection, in most cases it freezes the user's system.
Solution - precalculations based on source dimensions and zoom factor