JPG := TJPegImage.Create;
    try
      JPG.CompressionQuality := 100;
      JPG.Loadfromfile(extractfilepath(Application.exename)+'f.jpg');
      image1.Picture.Assign( JPG );

    finally
      FreeAndNil(JPG);
    end;

   // Test 1
   try  
     ...
     ImageEnView1.IEBitmap.Assign( jpg);
    finally
      FreeAndNil(JPG);
    end;

   // Test 2
   try
    bmp:=TBitmap.Create;
    bmp.Assign(imgPlotAna.Picture.Bitmap);
    ImageEnView1.IEBitmap.Assign(bmp);
    bmp.Free;
 
    // Test 3  - Using assign directly from TJPeG
    ImageEnView1.Assign(JPG);  

    // Test 4  - Assign from timage.bitmap to ImageEnview.bitmap
    ImageEnView1.Bitmap.Assign(image1.Picture.Bitmap);

ImageEnView1.IEBitmap.Assign( image1.Picture );
ImageEnView1.Update();

ImageEnView1.Assign( image1 );