Mailing lists / lazarus / 2010-11
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Hi, I'm loading PGM files to an TImage.Picture using its LoadFromFile or LoadFromStream methods.
This works well on small to medium sized images, but I'm getting an "EReadErrorEReadError" exception if I try to load images of 16mb or more.
Does anyone knows how can I workaround this?.
The problem is in fpreadpnm.pp (fpc/packages/fcl-image), in the method:
procedure TFPReaderPNM.InternalRead(Stream:TStream;Img:TFPCustomImage);
var
Row:Integer;
l: Integer;
begin
ReadHeader(Stream);
Img.SetSize(FWidth,FHeight);
FScanLineSize:=FBitPP*((FWidth+7)shr 3);
GetMem(FScanLine,FScanLineSize);
try
for Row:=0 to img.Height-1 do
begin
ReadScanLine(Row,Stream);
WriteScanLine(Row,Img);
end;
finally
Row := l;
FreeMem(FScanLine);
end;
end;The ReadScanLine method uses the FScanLineSize to read from a Stream using Stream.ReadBuffer with a size of FScanLineSize, and it seems like in my image, in a specific row (4734 to be clear) it has a different line size than the expected by FScanLineSize.
Maybe the formula used to calculate the scan line size is wrong?.
I can open my image with many viewers like Eye of Gnome, or Gimp without problems.
I attached the problematic image here:
http://www.tarjeta-salud.com.ar/downloads/salida.pgm
Can you create a bug report with a small example program and this image attached?
Mattias
Done, please take a look here:
http://bugs.freepascal.org/view.php?id=17840