[Newbies] How to use Form pixelCompare:with:at:

[Herbert König]

Am 07.01.2014 16:23, schrieb Bert Freudenberg:
> On 07.01.2014, at 16:13, Herbert König <herbertkoenig at gmx.net> wrote:
>
>> Hi Bert,
>>
>> Am 07.01.2014 15:57, schrieb Bert Freudenberg:
>>> Try 16 bit forms. - Bert -
>> thanks, that works.
>>
>> Is this a bug or infeasible with 32 Bit Forms? it's surprisingly fast. (I'm dealing with Photos)
> It's using BitBlt so should be fast indeed. Sounds like a bug that it does not work in 32 bits, at least according to the comment.
>
> OTOH all the BitBlt tally operations only work up to 16 bit depth. With 32 bit forms you could easily overflow a SmallInteger. So you might want to reduce the depth of the forms anyway before comparing.
>
How convenient that asGrayScale (I use that anyway) makes it 8Bit deep.

-Herbert