best way to sharpen photos?

I scanned an old photo with a hi res scanner. The resulting scan has a lot
of noise and is not very sharp.

There are programs like neatimage to reduce noise that is more sophiscated
than the blur filter in photoshop. Are there also sophiscated program to
sharpen the photo? I tried unsharp mask, smart sharpen, etc. They help only
a little bit.

Specifically, all the sharpen filter I've tried works by increasing
contrast. Therefore, any large amount of sharpening would results in patches
of bright spots.

Is there a sharpen filter that works by moving pixels around? So if you have
a blurring line, by squeezing the pixels closer together, the line would
become thinner and therefore sharper.

I have scanned some old photos too and used Adobe Photoshop Elements 4
to 'fix' them. I also used Infranview, which can be downloaded off the
net. http://www.irfanview.com/



peter wrote:
I scanned an old photo with a hi res scanner. The resulting scan has a lot
of noise and is not very sharp.

There are programs like neatimage to reduce noise that is more sophiscated
than the blur filter in photoshop. Are there also sophiscated program to
sharpen the photo? I tried unsharp mask, smart sharpen, etc. They help only
a little bit.

Specifically, all the sharpen filter I've tried works by increasing
contrast. Therefore, any large amount of sharpening would results in patches
of bright spots.

Is there a sharpen filter that works by moving pixels around? So if you have
a blurring line, by squeezing the pixels closer together, the line would
become thinner and therefore sharper.

How you scan the image can make a big difference in the final result. This
includes issues like dpi, exposure/contrast settings etc.
Also it sounds like you want to modify the original which is likely not very
sharp, has less than optimal contrast and likely has surface damage.
The latter defects, scratches/blotches/tears can really only be repaired
optimally by tedious cloning.
If you try to increase the contrast, sharpness etc beyond what is in the
original photo you will inevitably get a distorted appearing result.
Also enlarging the image will inevitably lead to some form of distortion.
It is not clear if you are objecting to what you see in magnified portions
of the image on your computer screen or how it ultimately looks in a print.
These are not necessarily the same.

silvercelt wrote:

peter wrote:
I scanned an old photo with a hi res scanner. The resulting scan
has
a lot of noise and is not very sharp.

There are programs like neatimage to reduce noise that is more
sophiscated than the blur filter in photoshop. Are there also
sophiscated program to sharpen the photo? I tried unsharp mask,
smart sharpen, etc. They help only a little bit.

Specifically, all the sharpen filter I've tried works by increasing
contrast. Therefore, any large amount of sharpening would results
in
patches of bright spots.

Is there a sharpen filter that works by moving pixels around? So if
you have a blurring line, by squeezing the pixels closer together,
the line would become thinner and therefore sharper.

I have scanned some old photos too and used Adobe Photoshop Elements
4
to 'fix' them. I also used Infranview, which can be downloaded off
the net. http://www.irfanview.com/


I've improved some pretty sad old pictures (after laboriously cloning
out scratches, spots, etc) by doubling their resolution (300 to 600
ppi, or 600 to 1200 on small prints, for eggsample) at scan-time,
doing a mild gaussian blur (1.3 pixels radius seems to work OK,
usually), and then reducing to working resolution (300 ppi, usually).
Treating this upped and downed version as an original while leveling,
coloring, curvesing, saturationing and finally sarpening, seems to
make an old ugly a bit prettier.

Here's one from a messy, yellowed 3.5 x 3.5-inch Instamatic drugstore
print (remember they gave you one that size and one "wallet-size" on a
single sheet?) :
http://www.fototime.com/2C71B7806D3648B/orig.jpg

--
Frank ess

peter wrote:
I scanned an old photo with a hi res scanner. The resulting scan has a lot
of noise and is not very sharp.

There are programs like neatimage to reduce noise that is more sophiscated
than the blur filter in photoshop. Are there also sophiscated program to
sharpen the photo? I tried unsharp mask, smart sharpen, etc. They help only
a little bit.

Specifically, all the sharpen filter I've tried works by increasing
contrast. Therefore, any large amount of sharpening would results in patches
of bright spots.

Is there a sharpen filter that works by moving pixels around? So if you have
a blurring line, by squeezing the pixels closer together, the line would
become thinner and therefore sharper.

Most sharpening functions I am familiar with work with the derivative
of the brightness vs distance from each pixel. That is, for each
pixel, it computes the rate of brightness change from the nearest
neighbors, the next nearest neighbors, out to many pixels away from the
one being considered. It then computes a function that INCREASES the
rate of change. In mathematical terms, it is essentially taking the
derivative of the linear rate of change. This is equivalent also to
high pass filtering a signal, and as a result it DOES increase noise.

The tools in photoshop and PSP are actually of several somewhat similar
sharpening functions, your choice, including the unsharp mask. The
latter works well, but you have to know what you are doing.

peter wrote:

I scanned an old photo with a hi res scanner. The resulting scan has a lot
of noise and is not very sharp.

There are programs like neatimage to reduce noise that is more sophiscated
than the blur filter in photoshop. Are there also sophiscated program to
sharpen the photo? I tried unsharp mask, smart sharpen, etc. They help only
a little bit.

Specifically, all the sharpen filter I've tried works by increasing
contrast. Therefore, any large amount of sharpening would results in patches
of bright spots.

Is there a sharpen filter that works by moving pixels around? So if you have
a blurring line, by squeezing the pixels closer together, the line would
become thinner and therefore sharper.

Tools like unsharp mask do not actually sharpen, they increase
accutance, or edge contrast. To actually sharpen, you
need tools like:

Image Restoration Using Adaptive Richardson-Lucy Iteration
http://www.clarkvision.com/imagedeta...e-restoration1

However, to use such tools, you need high signal-to-noise
ratios, of which film has little. The cost is increased noise,
and extreme use gives artifacts, just like with other tools such
as unsharp mask.

Roger