A source image is transformed into a destination image having a target aspect ratio. A reference region in the source image is defined. An extended region of interest of the source image having the target aspect ratio and containing the reference region is defined. A set of candidate image regions of increasing resolutions from the extended region of interest is determined, each having the target aspect ratio and containing the reference region. Candidate image regions are scaled to form a candidate target images. A quality metric is used to select a target image providing the best quality metric value.