This is working for me.

PICTField: TIB_ColumnBlob;
Image1: TImage;


var b:TBitmap;
ji1:TJpegImage;
begin
if OpenPictureDialog1.Execute then begin
b:=TBitmap.Create;
ji1:=TJpegImage.Create;
if uppercase(ExtractFileExt(OpenPictureDialog1.FileName))='.BMP' then begin
b.LoadFromFile(OpenPictureDialog1.FileName);
JI1. Assign( b );
JI1.Compress;
Image1.Picture.Assign(JI1);
b.Assign(Nil);
PICTField.Assign( JI1 );
end;
if uppercase(ExtractFileExt(OpenPictureDialog1.FileName))='.JPG' then begin
Image1.Picture.LoadFromFile( OpenPictureDialog1.FileName );
JI.Assign( Image1.Picture );
PICTField.Assign( JI );
end;
PicSize.Caption:=Format('Bildgrösse: %d KB',[trunc(PICTField.BlobSize/1024)]);
b.free;
ji1.Free;

Mit freundlichem Gruss & Best Regards

Andreas Pohl
apohl@...
www.ibp-consult.com