I need convert jpeg2000 for a blob field. After converted the image, it need save to file. And I do it like this
// if field need to convert
if qr.FieldByName('ext').AsString = 'jp2'
then
begin
Img := TSingleImage.Create;
mem_st := TMemoryStream.Create;
// convert
try
TBlobField(qr.FieldByName('img')).SaveToStream(mem_st);
mem_st.Position := 0;
Img.LoadFromStream(mem_st);
str_file_path := qr.FieldByName('img_name').AsString + '.jpg';
Img.SaveToFile(str_file_path);
finally
mem_st.Free;
Img.Free;
end;
end
In result - image is a black square.
Help me please.