Hi,

Today I saw?Color thief[1]?and I was impressed.I like to have something like this in my application so I reviewed the code but I dont know how to implement this in FreePascal or couldn't find anything like this in Pascal that do as good as this.

Any one know about a library like this in Pascal or Delphi or probably write similar to this?

Regards, Ara

Links:

1. https://github.com/lokesh/color-thief

TFPCustomImage can do this for you.
Load the image, set UsePalette:=True, and then the palette is available in the Palette property.

Michael.

Thank you.

I get exception when try to load from file and I could not debug in FPC source,debugger don't go there:

Also is there a class to do file loading with readers automatically like TImage? Tlazintfimage seems not does this . yes its not hard to implement it but as just now I find out there is many things in Lazarus and FreePascal that I'm not aware of them!

Regards, Ara

What is the exception you get ?

The loading should go automatically, provided you have included the necessary reader files (fpreadjpeg.pas) in your uses clause.

Michael.

Project project1 raised exception class 'External: SIGSEGV'.

File exists and it is correct.

Ara

For now I used lovely BGRABitmap like this,thanks to its author circular.

Regards, Ara

aradeonas wrote

Project project1 raised exception class 'External: SIGSEGV'. ? File exists and it is correct.

Can you send me the file ?

Michael.

Here you are.

http://lokeshdhakar.com/projects/color-thief/img/photo1.jpg

Ara

aradeonas wrote

Here you are. http://lokeshdhakar.com/projects/color-thief/img/photo1.jpg

Your program contained an error, I should have seen used TFPCustomImage. This is an abstract class. You should have used a descendent like TFPMemoryImage instead. (
the compiler warns you:
testpalette.lpr(10,37) Warning: Constructing a class "TFPCustomImage" with abstract method "SetInternalPixel" )

So:

program testpalette;
uses fpimage,fpreadjpeg;
var
   i: Integer;
   Img: TFPCustomImage;
begin
   Img := TFPMemoryImage.Create(0, 0);
   try
     img.LoadFromFile('photo1.jpg');
     img.UsePalette := True;
     for i := 0 to img.Palette.Count-1 do
       With img.Palette.Color[i] do
         Writeln(red,',',green,',',blue);
   finally
     Img.free;
   end;
end.

Works as expected.

Michael.

My bad!

I test the code but app will wait for more than a minute and so on on "img.UsePalette := True;" and I couldn't get values.I test that image in Lazarus/FPC Trunk 2015/06/27 49452.

Regards,
Ara

aradeonas wrote

I test the code but app will wait for more than a minute and so on on "img.UsePalette := True;" and I couldn't get values.

It took a while here... just under a minute, but then it started writing out all the RGB values. So it works, but it just ain't fast because the palette is huge (as expected).

Regards,
- Graeme -

So in my case BGRABitmap is a better choice,because I could choose color count.
Thank you Michael and Graeme as always.

Regards,
Ara

Well, I have faster palette creation on my list.
But it will always take a while, since the palette will be huge in each case. A palette with too many colors is nonsense anyway.

Michael.