BeRoPNG - A very tiny but complete PNG loader

[Cybermonkey]

Sorry, I know this is an old thread but I tried BeRoPNG to work with ptcgraph. This is my (simple) example:

var
  f: file;
  fsize: longword;
  buffer: pbyte;  
  ImageData: PPNGPixel;
  ImageWidth,
  ImageHeight:longint;
    gd,gm:smallint;
BEGIN
  AssignFile(f, 'bluepointer.png');
  Reset(f, 1);
  fsize := FileSize(f);
  buffer := getmem(fsize);
  blockread(f, buffer^, fsize);
  CloseFile(f);

  BeRoPNG.LoadPNG(buffer, fsize, ImageData, ImageWidth, ImageHeight, false);
  
  Gd:=D16bit;
  Gm:=m800x600;
  InitGraph(Gd, Gm, 'Test'); 
  
  
   if GraphResult <> grOk then begin
         Writeln('Graphics error: ', GraphErrorMsg(ErrorCode));
    Halt(1);
    end;
  
  putimage (10,10,imageData^,1);
  delay (2000);
  closegraph;
  
  
  freemem(buffer);
  freemem(ImageData);
    
   
END.

But the result isn't correct (see the attached screenshot). I think the problem is that ptcgraph uses a 16 bit colour format with no alpha channel. Any ideas how this can work?
beropngtest.jpg