Automated straightening of skewed text scans?

I have a large number of high-resolution, full-color scans of a
(primarily) text document. Unfortunately, many of the scans are
visibly skewed at different angles (i.e., where the text is not
horizontal).

I'd like to straighten out these skewed images while preserving as
much of the image quality as possible, and to do it quickly.

Of course, I can de-skew these images manually in Paint Shop Pro
using the "free rotate" feature, and by trial and error (by setting
the correct angle of rotation), can get the text lines reasonably
horizontal.

Unfortunately, this is laborious when one has almost 500 scans to do
(and possibly many more in the future.)

As a possible solution, OCR applications autodetect when text lines
are not perfectly horizontal and do the necessary rotation before they
perform OCR. However, the three I tried (ABBYY Reader, OmniPage and
TextBridge), do other pre-processing on the images, so the saved
de-skewed images have been altered much more than what PSP-by-hand
gives (which is pretty faithful to the original source.) OmniPage and
TextBridge lower the resolution and filter the images (entirely
unacceptable), while ABBYY preserves the input resolution and
color-depth, but does some odd subtle filtering (also unacceptable --
I could not turn this off in ABBYY.)

So what are my options? (Any other OCR to try?)

If I have to do this manually, I'd certainly like the process to be
faster and more fool-proof, without need to do any trial and error.

What sayest the experts? Please reply in this newsgroup if you can
(the return email address does not work.) Are there any other forums
I can post this request to?

Thanks.

Mark

Photoshop CS has an automatic 'Straighten and Crop" function, but it's hard
to justify the expense just for your purposes.

Maris

Mark wrote:
> I have a large number of high-resolution, full-color scans of a
> (primarily) text document. Unfortunately, many of the scans are
> visibly skewed at different angles (i.e., where the text is not
> horizontal).
>
> I'd like to straighten out these skewed images while preserving as
> much of the image quality as possible, and to do it quickly.
>
> Of course, I can de-skew these images manually in Paint Shop Pro
> using the "free rotate" feature, and by trial and error (by setting
> the correct angle of rotation), can get the text lines reasonably
> horizontal.
>
> Unfortunately, this is laborious when one has almost 500 scans to do
> (and possibly many more in the future.)

Take a look at SCANFIX - it allows precise user control of the process
of deskewing, removing horizontal and vertical lines, removing speckes,
etc.

Pretty pricey - as I recall it's something like $1600. I've never
upgraded my 5-year-old version, due to sticker shock, but it always
does what I need.