(SOLVED) Convert PNG transparency in white color

[AsleyCruz]

Hi coders,

I have an PNG file with transparency in a TImage. I save it in JPG format but the transparency has black background.
Is there a function to convert the transparency in white color?

Many thanks a lot.

[winni]

Hi!

Why do you want to do that??

JPG has no transparency, it is a lossy format and with high compression it has a lousy quality.

Anyway:

Code: Pascal  [Select][+][-]

1. Uses .... BGRAbitmap, BGRAdefaultBitmap;
2.  
3. ....
4.  
5. var BGRA: TBGRAbitmap;
6.  
7. begin
8. BGRA := TBGRAbitmap.create (Image1.Picture.Bitmap);
9. BGRA.ReplaceColor (BGRAPixelTransparent, clWhite);
10. BGRA.Draw (Image1.Canvas,0,0);
11. BGRA.Free;
12. .....

Winni

[lucamar]

One other, maybe more simple, way (without resorting to 3rd party libs) would be to create a white TBitmap of the proper dimensions, draw the PNG over it and convert that to JPEG.

[AsleyCruz]

Hi!

Why do you want to do that??

JPG has no transparency, it is a lossy format and with high compression it has a lousy quality.

Anyway:

Code: Pascal  [Select][+][-]

1. .....

Winni

Many thanks winni but I dont know what I am doing wrong.
Please see attached image. Tested in a blank document.

[winni]

Hi!

Sorry - I forgot in the uses

BGRAbitmapTypes;

That's the whole secret.

Winni

[AsleyCruz]

Hi!

Sorry - I forgot in the uses

BGRAbitmapTypes;

That's the whole secret.

Winni

Thanks Winni, it works and replaces transparent color of any BMP image only.
Unable to replace transparent color on PNG files.

Thanks

[lainz]

Create a white bgrabitmap of the same size of the image. Then draw on top of it your transparent image.

[AsleyCruz]

Create a white bgrabitmap of the same size of the image. Then draw on top of it your transparent image.

Hi Lainz

What I tried, it replace all red background :/
Any idea to drop the PNG file?

Thanks a lot

Code: Pascal  [Select][+][-]

1. BGRA := TBGRABitmap.Create(256,256,clred);

[lainz]

Code: Pascal  [Select][+][-]

1. var
2.   bgBitmap, bgImage: TBGRABitmap;
3.  
4. bgImage := TBGRABitmap.Create('image.png');
5.  
6. bgBitmap := TBGRABitmap.Create(bgImage.Width, bgImage.Height, BGRAWhite);
7.  
8. bgBitmap.PutImage(0,0,bgImage, dmDrawWithTransparency);
9.  
10. bgImage.Free;
11.  
12. bgBitmap.SaveToFile('image.jpg');
13.  
14. bgBitmap.Free;

[AsleyCruz]

Code: Pascal  [Select][+][-]

1. var
2.   bgBitmap, bgImage: TBGRABitmap;
3.  
4. bgImage := TBGRABitmap.Create('image.png');
5.  
6. bgBitmap := TBGRABitmap.Create(bgImage.Width, bgImage.Height, BGRAWhite);
7.  
8. bgBitmap.PutImage(0,0,bgImage, dmDrawWithTransparency);
9.  
10. bgImage.Free;
11.  
12. bgBitmap.SaveToFile('image.jpg');
13.  
14. bgBitmap.Free;

Oye, tu componente es excelente, lástima no conocer bien sus capacidades.
Apenas en 2 proyectos míos lo he usado, pocas líneas y grandes resultados.
Mil gracias bro.

[lainz]

Isn't mine. The author is circular
I only contribute in bgracontrols