Image format.
Default is JPEG.
If true, the encoder will spend extra time when saving JPEG files
to improve the compression rate. Enabling this option has no impact on quality.
Default is false.
Quality parameter is for JPEG only and is in range 0 to 100. If -1, then the value from hibernation is used. In case the ImageRef was created in lazy load-mode and originally has the same format as the requested to save, then setting quality to -1 leads to simply copying from source to destination, which is time efficient and prevents quality loss caused by decoding the JPEG and then re-encoding it.
Default is -1.
Options for encoding image.