Re: [GD-DEVEL] trasparent image width antialiasing

"Pierre" <[email protected]> ha scritto nel messaggio
news:[email protected]...
> On 2/1/07, yagyog <[email protected]> wrote:
>> ----- Original Message -----
>> From: "Pierre" <[email protected]>
>> To: "yagyog" <[email protected]>
>> Cc: <[email protected]>
>> Sent: Thursday, February 01, 2007 1:17 PM
>> Subject: Re: [GD-DEVEL] trasparent image width antialiasing
>>
>>
>> > On 2/1/07, yagyog <[email protected]> wrote:
>> >> ----- Original Message -----
>> >> From: "Pierre" <[email protected]>
>> >> To: "yagyog" <[email protected]>
>> >> Cc: <[email protected]>
>> >> Sent: Thursday, February 01, 2007 12:35 PM
>> >> Subject: Re: [GD-DEVEL] trasparent image width antialiasing
>> >>
>> >>
>> >> > Hi,
>> >> >
>> >> > On 1/30/07, yagyog <[email protected]> wrote:
>> >> >> ----- Original Message -----
>> >> >> From: "Pierre" <[email protected]>
>> >> >> To: "yagyog" <[email protected]>
>> >> >> Cc: <[email protected]>
>> >> >> Sent: Tuesday, January 30, 2007 3:48 PM
>> >> >> Subject: Re: [GD-DEVEL] trasparent image width antialiasing
>> >> >>
>> >> >>
>> >> >> > On 1/30/07, yagyog <[email protected]> wrote:
>> >> >> >> I have a problem, Excused but I do not speak English
>> >> >> >>
>> >> >> >>
>> >> >> >> I have in input one image png with antialising
>> >> >> >> with uniform solid background
>> >> >> >>
>> >> >> >> I would want
>> >> >> >>
>> >> >> >> 1) to eliminate the background
>> >> >> >> 2) recreate the channel alpha in order not to lose the 
>> >> >> >> antialising
>> >> >> >> on
>> >> >> >> the
>> >> >> >> text
>> >> >> >>
>> >> >> >> It is possible?
>> >> >> >> you can give me of the information ?
>> >> >> >>
>> >> >> >> I try this code but not work:
>> >> >> >>
>> >> >> >> //
>> >> >> >> //load a, load b  and create test
>> >> >> >> //
>> >> >> >> a = myLoadPng("a.png");
>> >> >> >> b = myLoadPng("b.png");
>> >> >> >
>> >> >> > Can you give us a link to the images a.png and b.png please?
>> >> >> >
>> >> >> > --Pierre
>> >> >> >
>> >> >> Yes
>> >> >> the color is changed but ,
>> >> >> it does not change nothing
>> >> >>
>> >> >> http://www.yag.altervista.org/varius/a.png
>> >> >> http://www.yag.altervista.org/varius/b.png
>> >> >> my result
>> >> >> http://www.yag.altervista.org/varius/test.png
>> >> >
>> >> > You have to use the alpha component in your image. So the blending
>> >> > will be done when you copy a or b over test
>> >>
>> >> >. But if the original  images do not contain any alpha components
>> >> Exact! :(
>> >>
>> >> , the anti aliasing being
>> >> > done against a given color (green and yellow in your case), you will
>> >> > have a visible aliasing.
>> >> >
>> >> Excuse I have not understood well
>> >> you could makes to understand me better. even with of the code
>> >
>> > There is no way to achieve what you want without using the alpha
>> > component in your images.
>> >
>> > Here is an example image:
>> > http://blog.thepimp.net/misc/test_text_aa_alpha.png
>> >
>> > Load it in gimp/gqview, you will see the alpha values in the edges.
>> >
>> therefore
>>
>> I cannot realize what I said with one image without channel alpha? 
>> solution
>> does not exist one practically
>>
>> And if I have one image with the channel alpha?
>
> Please load http://blog.thepimp.net/misc/test_text_aa_alpha.png in
> your image editor and read the alpha values of the text borders. You
> will see what I mean.

ok I have seen.

I have created two images with the channel alpha ba.png bb.png
and used the same code here the result

http://www.yag.altervista.org/varius/1/ba.png
http://www.yag.altervista.org/varius/1/bb.png
my result
http://www.yag.altervista.org/varius/1/test.png