Detect if fill image has transparency or not

Hi !

I would like to be able to detect wether a fill of type image contains transparency or not.

I’m developping a code exporter and there are multiple reason why this information would be useful, for example :

• knowing wether its more relevant to export as PNG or JPG (without having to ask the user)

• knowing wether a shadow effect applied to that image should rather be handled in CSS (in the case of a jpg without transparency) or should be integrated in the export (in the case of a png with transparency)

please let me know if there’s any way to know this, (even a work-around)

Best regards.