[fpc-devel] Extract the color data and alpha from a PNG image

[silvioprog]

2013/2/5 Mattias Gaertner <nc-gaertnma at netcologne.de>

> On Tue, 5 Feb 2013 12:37:24 -0200
> silvioprog <silvioprog at gmail.com> wrote:
>
> > Hello friends,
> >
> > I'm trying to extract the color data and alpha from a PNG image. In PHP
> it
> > is very easy to implement, but in FPC I don't know how to do it. I tried
> to
> > do it via "chunk.data", "ZData" etc., but, without success.
> >
> > Attached two files to test it. To test the PHP code run this command in
> > your terminal:
> >
> > php -f fpdf.php
> >
> > The in FPC code is partially complete.
>
> Have you tried fpimage?
>
> uses
>   fpreadpng, fpimage;
>
> var
>   image: TFPCustomImage;
>   reader: TFPCustomImageReader;
>   x,y: integer;
>   c: TFPColor;
> begin
>   Image := TFPMemoryImage.Create(0, 0);
>   Reader := TFPReaderPNG.Create;
>   Image.LoadFromFile(AFileName, Reader);
>   for y:=0 to Image.Height-1 do
>     for x:=0 to Image.Width-1 do begin
>       c:=Image.Colors[x,y];
>       writeln(c.Alpha,' ',c.Blue);
>     end;
>   //...
>
> Mattias


Yes, I tried it too, but, without success. :(

See my new code in attached. It generates the data, but with wrong content.

-- 
Silvio Clécio
My public projects - github.com/silvioprog
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