Aplha8 Configuration for External Images

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asked Jan 16 in GUI Development by Chaitra
Hi Team,

We are Using the Extern image concept for storing and retriving the images from external memory source.

We are able to achive that in Native Image format.

When we change the Format to Alpha8 and tring the apply that we are not able to get the results.

how to get the alpha values of an Image and apply it??

we are trying to change the color of external images in runtime.

 

Reference link:

https://doc.embedded-wizard.de/ansic-gfx-xbitmaplock?v=9.20

Regards,

Chaitra

1 Answer

0 votes
answered Jan 16 by Manfred Schweyer
Hello Chaitra,

the Alpha8 image format is a one byte per pixel format and each pixel is used as an alpha value: 0x00 means full transparent and 0xFF means full opaque (full colored).

I think the problem in your EwLoadExternBitmap() implementation is the color conversion from your source color format into this Alpha8 format. Correct?

Do you have a source image that contains an alpha channel (e.g. some RGBA format) or do you have an image without alpha channel and you want to convert that into some gray values that should be used as alpha values?

Can you share an example of what you have and what you want to get? Then it should be possible to find a solution....

Best regards,

Manfred.
commented Jan 17 by Chaitra

Hi Manfred,

I think the problem in your EwLoadExternBitmap() implementation is the color conversion from your source color format into this Alpha8 format. Correct?

correct, we trying for the same.

Can we have any similar example for acessing an external image with Alpha8 properties??

Regards,

Chaitra.

commented Jan 17 by Manfred Schweyer

Hi Chaitra,

unfortunately, there is no similar example - but it should not be a big thing to change the color copy loop from 4 bytes RGBA to 1 byte alpha.

The question is still what you want to do:

Do you have a source image that contains an alpha channel (e.g. some RGBA format) or do you have an image without alpha channel and you want to convert that into some gray values that should be used as alpha values?

Can you share an example of what you have and what you want to get? Then it should be possible to find a solution....


Best regards,

Manfred.

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