Image.Save (gb.qt4)
Sub Save ( Path As String [ , Quality As Integer ] )
Saves the image to a file. The file extension of
Path will give the format
of the saved image.
Supported formats are JPEG, PNG, BMP, possibly GIF and XPM depending on the toolkit and system.
The range and interpretation for the Quality argument depends on the toolkit used: for
gb.gtk it is [0; 100] whereas
gb.qt4 can have [-1; 100]. -1 in gb.qt4 means to use default settings. Portable programs should restrict themselves to [0; 100]. 0 means good compression and bad quality.
For PNG files Quality translates to "compression", being a "lossless" format the file size will vary but the quality remains the same.
Since 3.19
GTK+ now supports the quality parameter with png format.
Be aware...
Image.Save and Picture.Save are managed by the underlying toolkit (QT, GTK+) and the list of supported formats is dynamic depending on the system so functionality/availability can vary.
For universal compatibility the Quality parameter should only be considered relevant to quality for JPEG images and compression for PNG.
Also, depending on the system, formats other than PNG, JPEG, BMP may or may not be available, there are no guarantees.
See also