After further fixes i tested these forms successfully:


#(
pal_bk pal rgba8_bk rgba8 rgba16_bk rgba16
rgb8_t_bk rgb8_t rgb16_t_bk rgb16_t
gray8a_bk gray8a gray16a_bk gray16a
gray8b_bk gray8b gray16b_bk gray16b
pal_bk_notrns palb
)
 do: [:e |
(ImageReadWriter formFromStream: ('
http://entropymine.com/jason/testbed/pngtrans/',e,'.png') asUrl
retrieveContents contentStream) asMorph openInWorld].



2014-05-10 12:36 GMT+02:00 Nicolas Cellier <
nicolas.cellier.aka.nice at gmail.com>:

> I just committed a fix.
>
> The PNGReadWriter currenlty has a hack to support 16 bits per channel gray
> scale (with a slow bit poker loop), but not with transparency...
> - transparency is handled with a palette
> - ColorForm only supports depth <= 8
> Since the Form is forced to depth 8, and since we must choose an entry in
> the palette for transparency,  I forced the transparency to be stored at
> 1st palette entry (value 0) in case of 16 bitsPerChannel.
>
> It seems to me that there was another bug even for bitsPerPixel <= 8: the
> palette is 1-based indexed so transparent color index was one off.
>
> It also seems to me that the inversion 255-pixelValue is wrong in the 16
> bitsPerChannel bitPoker loop , I did change it.
>
>
> 2014-05-09 19:36 GMT+02:00 Yoshiki Ohshima <Yoshiki.Ohshima at acm.org>:
>
> On Fri, May 9, 2014 at 1:14 AM, Bert Freudenberg <bert at freudenbergs.de>
>> wrote:
>> > Do we support any 16 bit-per-channel gifs?
>>
>> Not sure what you mean by "gifs" (I am specifically talking about
>> PNGs), but sure, I think Squeak should be able to read a PNG file, as
>> long as it is a valid one.  If it is 16 bits per channel, it should
>> downscale the depth to 8 and create a 32 bpp Forms.  This does happen
>> in most of the cases, but when the PNG file specifies the transparent
>> pixel (it is also in 16 bit value), it causes an error.
>> --
>> -- Yoshiki
>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.squeakfoundation.org/pipermail/squeak-dev/attachments/20140510/8042902f/attachment.htm