Browsing Chinese (Simplified) translation

918.

This transformation may introduce small image distortions along one or more edges, because the image dimensions are not multiples of 8.

The distortion is reversible, however. If the resulting image is unacceptable, simply apply the reverse transformation to return to the original image.

You can also choose to discard (or trim) any untransformable edge pixels. For practical use, this mode gives the best looking results, but the transformation is not strictly lossless anymore.