Archived Data Techniques Forums

Hi,

What's the best way to convert TIFF files from a fax machine into separate JPG files?

If I leave the default settings, when I receive a 70K three page TIFF

COMPRESS True

TIFF_COMPRESS GROUP4

And save this as JPG's I get three 800K pages.

If I set LOSSY_QUALITY to one I get three 98K pages (and the quality is quite bad).

Is there any way I can get three JPG's that total 70K?

(am I missing some JPG attributes - I'm only setting the LOSSY_QUALITY at present).

Code snippet

procedure TForm1.Button1Click(Sender: TObject);
var
  aImageMan : TImageControl;
  imageCount : integer;
  newFilename : string;
  attrs : OleVariant;
  iLossy : integer;
begin
  if OpenDialog1.Execute then begin
    attrs := CreateOLEObject('IMActX8.Attributes');
    aImageMan := TImageControl.Create(nil);
    try
      aImageMan.Picture := OpenDialog1.FileName;
      attrs.Add( 'EXTENSION', 'JPG',  IMString);
      TryStrToInt( edtLossy.Text, iLossy);
      attrs.Add( 'LOSSY_QUALITY', iLossy,  IMInt32);
      for imageCount := 0 to aImageMan.Pages -1 do
      begin
        aImageMan.PageNumber := imageCount;
        newFilename := CreateTempFile('.jpg');
        aImageMan.SaveAs(newFilename, attrs);
      end;
    finally
      aImageMan.free;
    end;
  end;
end;
 

Thanks,

Ben

Hi Ben,

For TIFF compression Group 3 is good for black and white images and Group 4 is best for black and white document type images.  JPG is intended for continous tone color images.  We're curious as to why you'd want to seperate each of the TIFF pages into separate JPG's.

Our best advice here, if you want to continue down the JPG route, is to set the loss quality to whatever gives you the maximum amount of compression and best quality for your situation (although you've already noted that the value of 1 will not work for you).  As you know already, JPG is not a lossless format and there are tradeoffs to be made depending on your use cases.

Hi Brian,

Thanks for the quick response.

The user wants to add layers to the image - ticking items, narratives etc (adding coloured icons for there tick - yes this is fine - red cross, this is wrong, different size and colour narative). as they view each page, they also want to detach pages as page 1-3 may relate to one deal 4 to another and 5 and 6 to another. Pages may be out of sequence, or a single page may contain multiple deals - so spilt the page and show colour split markers.

We moved the TIFF to separate JPG images to ease the re-ordering adding colour etc. as our Delphi components worked well with JPG's.

For users with uncompressed TIFF's the JPG conversion makes their documents (database) much smaller - for users with compressed TIFF's - I'm making them much bigger :o(

I wondered if there was a way to get close to the Group4 compression with JPG's - it looks like I need to re-think the design and use the compressed TIFF if that's what we're given.

Thanks again,

Ben

Ben,

Not to sound too much like a salesman, but our upcoming new release of ImageMan.NET will contain a new feature for annotating images which sounds like what you are trying to do.  We handle images, shapes, text, etc.  It should be out by the end of the month.  However, if you would like to give it a try to see if will cut back on your own custom coding, I could hook you up with a beta release.  If you are interested, let me know.  The annotation feature (and several other goodies will be part of an extended feature set called the Document Edition).

However, after typing this, I realize that you are using Delphi and so are probably using the OCX version of ImageMan.  Is that correct?