Operation Photo Rescue's Online Community

OPR Announcements => FAQ => Topic started by: dle on March 16, 2013, 05:35:33 PM

Title: Scanning Instructions?
Post by: dle on March 16, 2013, 05:35:33 PM
Recently I got to wondering about what instructions the wonderful folks who go out into the community and do the scanning receive. I ask because on a number of the photos I've done, there is a good deal of quantization error and many jpeg and sharpening artifacts.

I suspect these sorts of artifacts could be reduced through better scanning techniques. If there's something I can do to help on the intake end, I'm willing to work on it.

Thoughts? Comments?

David Ehnebuske
Title: Re: Scanning Instructions?
Post by: Pat on March 16, 2013, 08:25:17 PM
Hi David,

All of our photos are taken by digital cameras on copy stands or tripods during our copy runs.  Scanning is not as fast as by digital camera and the quality is better the way we do it.  Photos coming in are dirty and some have either glass or pieces of plastic album still attached which would rule out scanning. 

Here is a link to one of many fun spots on the OPR Forum that will show you more about our copy runs:  http://www.operationphotorescue.org/forum/index.php/topic,3644.0.html

Title: Re: Scanning Instructions?
Post by: dle on March 17, 2013, 01:27:58 PM
Thanks, Pat, for the reply. The copy run photos and commentary are really great. Thanks for the link. It looks like a) a lot of work, b) a lot of fun, and, c) very rewarding. I hope someday I can participate in one.

I guess I didn't ask my question correctly, though. It makes good sense, as you say, to use a copy camera instead of a scanner. It's faster and you can capture a wider variety of material. My question was less about scanning, per se, and more about the steps that are taken to try to avoid the many artifacts that tend to creep into captures whether done with a scanner or a copy camera. The particular examples I have encountered seem to be jpeg and sharpening artifacts.

Many of the photos I've worked on are very well captured. But on some there's significant "banding,"particularly in dark areas, with borders that zig and zag at 8x8-pixel intervals. And on some there are spots (dirt, no doubt) that are dark with light borders around them or light with dark borders.  Both look to me like they may have been introduced during the capture process.

If this sounds critical, I apologize. I don't mean it to be. I just know from doing many many captures that it's not easy to get right time after time. And I know from doing lots of them that the quality of a restoration depends, in part, on how faithful the capture is to the original. And I want OPR restorations to be as good as they possibly can be.

Title: Re: Scanning Instructions?
Post by: Pat on March 18, 2013, 11:05:16 AM
Thank you David for clarifying your question.  No need to apologize, and no you don't sound critical.  It's clear you are just trying to be helpful which is very much appreciated.  Thank you for bringing this matter to our attention.  Your concerns are being looked into.


Title: Re: Scanning Instructions?
Post by: jensend on February 18, 2014, 07:25:32 AM
I'm having the same issue with JPG image quality. There are very obvious 8x8 pixel blocks. The blocks may not show up when printing the image, but it makes it hard to see detail in partially damaged areas, especially when viewing only a single channel. The low quality of the image means it takes more time for me to restore the image.
I'm new here, and I'm only working on my second image, so I don't know how widespread the issue is.  The images I got were color corrected before I received them, so maybe they lost quality when they were saved after the color correction.
The test image I was given during the registration process had almost no visible blocks, and had over twice as many bytes per pixel in the file size.

Title: Re: Scanning Instructions?
Post by: Mhayes on February 18, 2014, 01:29:38 PM
Hi David,

Great to see you on the Forum. Your question would probably have been been better as new topic, because as mentioned we do not scan our photos. The reason your photo had a color correction before you got it was because it gets to be a real headache on wedding photos to have them come in with a wide range of color corrections. When you compare the quality of your test photo to your present work in progress photo is like comparing apples to oranges and I'll explain why. The test photo was in better shape to begin with and may not be as old as the photo you are working now. As a quick guess I would say these wedding photos are at least 40 years old and they don't look like they were taken by a professional photographer. Add age, dust, and flood damage--what you see is exactly how the photo was. Also, consider the fact that different photos are not printed on the same paper.

Once again, we do NOT SCAN photos at copy runs. This group of photos was taken on a copy stand with a Canon EOS 5D Mark II with a very good fixed lens and the white balance was done with the Expo Disc and the jpg saved at quality 10 at 300 dpi resolution. Short of saving as a TIFF which isn't even reasonable, this photo had the same image quality as your test photo. Does it look the same? Of course not. As to the image quality suffering because of the color correction--it did not.

Your test photo may have had more bytes per pixel because it was saved at Quality 12 instead of Quality 10 that is the norm. Since this photo has a file size of 1.4 MB it still has plenty of pixels. You might find it interesting to note that Almay (premier stock photo site) requires all of its JPGs to be at Quality 10.

Hope this helps explains the quality of your photo versus the quality of the capture.


Title: Re: Scanning Instructions?
Post by: Bambi on February 18, 2014, 03:25:00 PM
Hi David:

Is it possible to post an image to show the artifacts? I'd like to see what you're describing.

Title: Re: Scanning Instructions?
Post by: jensend on February 18, 2014, 08:53:34 PM
I wasn't comparing the quality of the photos, I was comparing the quality of the jpeg compression.

The older and/or more damaged a photo is, the more important it becomes that less compression is used.

As I said, a quality setting of 10 may be fine for a stock photo, but when you're basically doing forensics on an image, any additional information is welcome.

here's an example of the blue channel on the image (LynnL_36_24_8x10.jpg) I'm working on (zoomed in 200%):

And here's the blue channel in the test image:
There are no discernible blocks in the test image.

here's an RGB example (I've adjusted the levels and zoomed in 200%):

Title: Re: Scanning Instructions?
Post by: Mhayes on February 18, 2014, 09:55:13 PM

I have sent you and the inner team an email where I have enclosed the original shot uploaded from the camera before it has been straighten, cropped, or color corrected. The second JPG is the original (still not cropped or corrected), but "Saved As" a JPG at Quality 12.

You be the judge on whether it is a help or not. If you use it, then cropped to the 8 x 10 dimension and use Quality 12. Also, color correct.


Title: Re: Scanning Instructions?
Post by: seelcraft on February 18, 2014, 11:35:28 PM
The particular examples I have encountered seem to be jpeg and sharpening artifacts.

And on some there are spots (dirt, no doubt) that are dark with light borders around them or light with dark borders.  Both look to me like they may have been introduced during the capture process.

Yes, I've often wondered about the "butterfly" defects that appear in some pix: dark spots with white wings, or vice versa. They're always all vertically oriented or all horizontally oriented. So they're clearly introduced at capture time. Is it bad lighting? or wacky jpeg defects? I thought you captured them as png's?!
Title: Re: Scanning Instructions?
Post by: Mike S. on February 19, 2014, 08:01:06 AM

For the most part all photos are taken on professional copy stands with professional lighting.  White balance is taken in all cases.  Usually all photos are saved at the time of capture as the highest JPEG's possible.  This is OPR policy because they have to travel over the Internet to the volunteers and sending Tiff files would increase file sizes tremendously.  It is impossible to remove in some cases all possible reflections even with Polarizing Filters because many photos have water damage which induces many ripples in the photo that are a nightmare to flatten even with heavy glass.   The lighting is controlled as much as possible.  At Seaside heights, New Jersey we were able to turn out the overhead lights but it is not possible in all cases so we have to work under the conditions given.  All lighting whether overhead or on the copy stand is relevant and that is why we do a custom white balance but it does not stop reflections in damaged photos.

I should also add that like you, all in OPR are volunteers.  We have limited funds but Photoshelter very kindly donates space for us to display, download and upload the photos to be restored but this is not unlimited so to keep operating we have to use the JPEG format.  That said we will also need donations to enable us to do copy runs this year.

Hope this helps explain why copy perfection with damaged photos is not possible in all cases.

Title: Re: Scanning Instructions?
Post by: Tori803 on February 19, 2014, 10:46:17 AM
Hi David,

As you can see from the comments, all volunteers are trying their best to accomplish OPR's mission. With your extensive experience we would value your assistance at the next copy run. Often we have to rely on local volunteers for help, many with very limited experience in photography or Photoshop. We're all looking for better ways to get things done and if you can show us some new techniques we'd be delighted!

Remember that anytime you download a photo to restore and find on closer examination that it's not one you want to tackle, please feel free to inform your distributor and make a different selection.