How to specify the Alpha layer in a Bitmap resource in ver 9.30?

asked Feb 17 in GUI Development by jhanchuruck

In EW versions 9.10 and earlier, the developer could specify the alpha layer for a Bitmap resource by setting the Alphaname property to the image file that contains the Alpha only image data. In EW version 9.20 and later, this property is no longer available.

How can i specify the alpha image data so that the primary image is alpha blended with the alpha image data?


1 Answer

+1 vote
answered Feb 17 by Paul Banach
Best answer


to achieve the same effects, specify the image file in the attribute FileName and the desired Alpha8 format in the attribute Format. We modified the attributes with the verion 9.20 in order to support more formats and conversion features. Please see also the indications in the description of the old attribute AlphaName.

If in your application case you have used originally two image files (one containing color information and the second containing opacity information), use a graphic editor (e.g. Photoshop) to compose the both image files to a single PNG file. The possibility to specify separate files for color and opacity has its origins in the limitation of BMP file format used many years ago. With PNG format such tricks are obsolete.

Does it help you?

Best regards

Paul Banach

commented Feb 18 by jhanchuruck
Hello Paul.

Thank you for your reply and your advice. Yes. This is very helpful.

As i now understand, version 9.20 or higher will not support the 2 file system (1 Color file & 1 Opacity file). Therefore, in my case, i will need to edit all bitmap resources that had called out 2 files and combine them into one file using an image editor.

Thanks again for your insight.

Best regards,

Jon H.
commented Feb 18 by Paul Banach
Hello Jon,

that is right. If you have many images to adapt, I would look for a graphic editor (or command line conversion tool) supporting batch jobs.

Best regards

Paul Banach

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