Bitmap and TWICImage

[limelect 53]

Out of curiosity, I have 2 functions, one OK, the other not

2 exact function, the PNG returns a white picture, the TIFF works

 

procedure BITMAPtoPNG2(MyBitmap: TBitmap; destinationfilename: string);
var
  MyWIC: TWICImage; // preserves transparency
begin
//  Assert(
  MyBitmap.PixelFormat := pf32bit; << it was 24 same result
  MyWIC := TWICImage.Create;
  try
    MyBitmap.AlphaFormat := afDefined;
    MyWIC.LoadFromFile(FileSave); <<<<<<<<<<<<<<<<<<<<<<I have to do that
  //  MyWIC.Assign(MyBitmap);  <<<<<<<<<<<<<<<<<<<<<<< this return white picture
    MyWIC.ImageFormat :=TWICImageFormat.wifPng ;//wifPng;
      if Form1.TestIfFileExist(destinationfilename) then
    MyWIC.SaveToFile(destinationfilename);
  finally
    MyWIC.Free;
  end;
end;
 

THIS IS OK

procedure BITMAPtoTIFF(MyBitmap: TBitmap; destinationfilename: string);
var
  MyWIC: TWICImage;
begin
  MyWIC := TWICImage.Create;
  try
    MyWIC.Assign(MyBitmap); <<<<<<<<<<<<< This is OK
    MyWIC.ImageFormat := TWICImageFormat.wifTiff;
      if Form1.TestIfFileExist(destinationfilename) then
    MyWIC.SaveToFile(destinationfilename);
  finally
    MyWIC.Free;
  end;
end;

[limelect 53]

I fixed it by bringing 

 b := TBitmap.Create;
  b.Assign(ImgView321.Bitmap);

Send B to functions

 

However, if I load b from a file, it does not work. (MyBitmap)

I still wonder. Any explanation?

Edited August 8 by limelect

[Anders Melander 2068]

TBitmap.AlphaFormat is broken beyond repair - literally.

 

See: https://quality.embarcadero.com/browse/RSP-26621

 

If you need to handle 32-bit RGBA bitmaps, use something that was designed for it.

[limelect 53]

Thanks, I thought so

As you can see, I fixed it differently

Edited August 8 by limelect

[DelphiUdIT 260]

1 hour ago, Anders Melander said:

TBitmap.AlphaFormat is broken beyond repair - literally.

 

See: https://quality.embarcadero.com/browse/RSP-26621

 

[Remy Lebeau 1642]

Why use TWICImage and not TPNGImage?