imread (repost)

[Shai Ayal]

On Tue, Aug 5, 2008 at 8:43 PM, Daniel J Sebald <daniel.sebald at ieee.org>wrote:

> Bill Denney wrote:
>
>  Currently (and also in matlab I believe) you can only view one image at a
>>> time. So my question is basically, what is behind image? Say I run the
>>> following
>>>
>>>  im = rand (100, 100, 4);
>>>  im (:, :, 4) = 1; # full transparancy
>>>  figure
>>>  imshow (im)
>>>
>>> What should I expect to see?
>>>
>>
>>
>> I would expect to see the axis background color.  If the axis background
>> color is set to none, then I would expect to see the figure background
>> color.  I believe that if you set the figure background color to none in
>> matlab, you see a cross-hatched pattern.  When exporting, I would anticipate
>> that the graphics backend would take alpha into account relative to the
>> output device, so if the output was to ps or pdf, it would convert the
>> background color to the color as visible on the screen.
>>
>> I'm not saying that this is easy, just that-- to me-- the above is the
>> right way to do it.
>>
>
> In my opinion, the right way is for PostScript to handle alpha blending.
>  Wish it would.  It's the easiest place to implement such a feature, i.e.,
> at the last step just blend the contents together.


Does postscript support blending?

Shai
-------------- next part --------------
An HTML attachment was scrubbed...
URL: https://www.cae.wisc.edu/pipermail/octave-maintainers/attachments/20080805/02f004c8/attachment.html