On Nov 13, 2011, at 12:34 PM, Quincey Morris wrote:
> On Nov 13, 2011, at 11:11 , James Merkel wrote:
>
>> This is kind of interesting -- if I rotate the image in Preview (rather than
>> Image Capture), then the histogram looks normal.
>> Looking at the NSBitmapImageRep from Preview image, the
On Nov 13, 2011, at 11:11 , James Merkel wrote:
> This is kind of interesting -- if I rotate the image in Preview (rather than
> Image Capture), then the histogram looks normal.
> Looking at the NSBitmapImageRep from Preview image, the order is RGBA and
> there is no reported alpha channel.
> Fu
On Nov 12, 2011, at 4:34 PM, James Merkel wrote:
>
> On Nov 12, 2011, at 3:29 PM, Quincey Morris wrote:
>
>> On Nov 12, 2011, at 14:01 , James Merkel wrote:
>>
>>> d' = a * s + (1 - a) * d
>>> All premultiplication does is precalculate a * s."
>>>
>>> First question -- what is d' in that equa
On Nov 12, 2011, at 3:29 PM, Quincey Morris wrote:
> On Nov 12, 2011, at 14:01 , James Merkel wrote:
>
>> d' = a * s + (1 - a) * d
>> All premultiplication does is precalculate a * s."
>>
>> First question -- what is d' in that equation?
>
> It's the result of compositing the source (your imag
On Nov 12, 2011, at 14:01 , James Merkel wrote:
> d' = a * s + (1 - a) * d
> All premultiplication does is precalculate a * s."
>
> First question -- what is d' in that equation?
It's the result of compositing the source (your image) onto the destination
(the background).
> I read images from
