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Topic: Transparent Pngs

At first I would like to thank authors for making such a nice program. The only problem i had experienced is making transparent PNGs - I tried to save normal (non-transparent) picture with transparent backgroun color, but the result was same as the original.. Maybe I am doing something wrong? Is there something special one must do?

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Re: Transparent Pngs

Did you set the correct transparent color key in the file format options dialog?
What pixel format is your image (8 bit / 24 bit)?
What program did you use to check/view the result?

Michael Vinther

> software developer <

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Re: Transparent Pngs

The Image is 24 bit. For checking the result i used IE 6.0 - I placed the picture on a html page with different backgrond texture. I heard IE supports transparent PNGs since version 4.0..

Here is what I was doing step-by-step:
1. I opend the image (uncompressed BMP)
2. File -> Save as..
3. select PNG format
4.  -> File format option
5. select transparent color key -> 24 bit -> black (in hex 000000) (i assured that there are lots of black pixels in the picture)
6. scan line filter: autodetect - try all, image quality lossless
7. close file format option dialog
8. -> save.

Thanks for your attention..

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Re: Transparent Pngs

As far as I know IE only supports transparency in 256 color PNGs properly.

If you open this link to a page with some PNG test images you will probably see that they are not displayed correct either. You can also try searching for internet explorer png transparent on Google.
Try using another browser like Opera - it has better PNG support.

Michael Vinther

> software developer <

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Re: Transparent Pngs

Thanks.. this clears things to me.. IE is so dumb as other Micro$oft products sad
(just one thing - on that page you've suggested, there are 32bit PNGs, wich means they've alpha channel, but that's other case than 24bit transparent PNGs with just one transparent color, isnt it?)

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Re: Transparent Pngs

Yes, you are right - alpha channel transparency is a different matter. I didn't notice that all of the pictures were 32 bit. Anyway, it demonstrates that the PNG support in Internet Exploder is not complete.

Michael Vinther

> software developer <