Author: Tomas Rutkauskas

How to retrieve and display a TJPEGImage from a Paradox blob field

Answer:

Solve 1:

Here's some code to fill a TImage on a form with a JPEGImage from a Paradox blob 
field:

1   var
2     Stream1: TBlobStream;
3     Photo: TJPEGImage;
4   begin
5     Stream1 := TBlobStream.Create(Table1.FieldByName('YourFieldName') as TBlobField, 
6   bmRead);
7     Photo := TJPEGImage.create;
8     try
9       Photo.LoadFromStream(Stream1);
10      Image1.Picture.Assign(Photo);
11    finally
12      Stream1.Free;
13      Photo.Free;
14    end;
15  end;



Solve 2:

Here is an example showing use of the TJPEGImage to display JPEG images in a TImage 
component. The JPEG data is stored in a Paradox BLOB field, and this routine is 
executed when the record pointer is moved in the table in order to display each new 
record's BLOB field contents.

16  procedure TForm1.Table1AfterScroll(DataSet: TDataSet);
17  var
18    MS: TMemoryStream;
19    J1: TJPEGImage;
20  begin
21    J1 := TJPEGImage.Create;
22    MS := TMemoryStream.Create;
23    try
24      TBlobField(DataSet.Fields[1]).SaveToStream(MS);
25      MS.Seek(soFromBeginning, 0);
26      with J1 do
27      begin
28        PixelFormat := jf24Bit;
29        Scale := jsFullSize;
30        Grayscale := False;
31        Performance := jpBestQuality;
32        ProgressiveDisplay := True;
33        ProgressiveEncoding := True;
34        LoadFromStream(MS);
35      end;
36      Image1.Picture.Graphic.Assign(J1);
37    finally
38      J1.Free;
39      MS.Free;
40    end;
41  end;