Print scanning - scanner and file format question

[cerebros]

Hi folks,

Been a while since I've posted on these forums.

I'm finally getting round to starting a long overdue project to scan in all the old family photos.  Unfortunately, given my mother's attitude to things, I don't have access to the original negatives so I'm going to have to scan everything from prints, the majority of which have spent a few decades in photo albums using sticky plastic page coverings (fortunately, from the sample I've looked at today, acid free).

Anyway, the flatbed scanner I've got at the moment is a Canon N650U which is a good few years old now, its spec being 600 dpi and (I think) USB 1.  While I'm aware that I'm unlikely to see any realistic gains in image quality from a higher optical resolution modern scanner, am I likely to see any improvements in scan speed with a more up-to-date scanner?  As the main time I'm going to be doing the scanning is on the weekly visits to my mum's with my daughter, I'm wanting to try and get as much done in the time as possible.

Next question is, what is the best file format to save the scans in?  My scanning program of choice is Vuescan which supports TIFF and DNG.  During my absence from these forums I've not really kept up on these things but is DNG starting to see wider support?  I notice it's still not so standardised as to be built into Windows (so I had to go download a codec to be able to view thumbnails and be able to edit meta data via the file properties, although to be fair they don't seem to include any codecs as standard).

thanks in advance

[Mark D Segal]

Being a USB 1 device at least 12 years old, it is more than likely you would get faster performance with a more up-to-date scanner using at least USB 2.0 connectivity. Before worrying about speed, I'd recommend that you try scanning some of these images first to see just how "scanable" they are in light of the plastic covering. I would recommend using TIFF file format. For scanning, DNG is just a container of a fully rendered three channel pixel-based image. You have the same with TIFF and just about any image editing application can read it.

[cerebros]

Before worrying about speed, I'd recommend that you try scanning some of these images first to see just how "scanable" they are in light of the plastic covering.

Sorry,should have made that clearer, it's card pages with a sticky/tacky backing that the plastic sticks to.  The plastic still lifts off so I'm able to scan the surface of the print - I have done a couple of test scans that did take a bit of a while (hence the question about likelihood of faster speeds with a newer scanner)

[Mark D Segal]

OK, if it scans the prints so you get usable results that's good. You don't say how long it took to scan - I suppose - the whole page of images - or just one image? And what size, and what resolution? What computer set-up are you using? All these things affect scan speed, as does your computer and software. So to benchmark your question, I did a few experiments that may be useful guidance for you. For reflective scans (flatbed of prints - your case) I use an Epson Perfection V750 Pro, connected to my MacPro OSX 10.6.8 by USB 2.0. I use SilverFast Ai8 Studio for scanning - as far as I could tell, not available for your scanner model, but Vuescan will work with your scanner. Anyhow, that's my set-up used for this benchmarking.

I don't know how large you want to print the scanned images, so I did a number of tests, with a colour image scanned in 48 bit depth:

8*11.7 inches at 600ppi (full page, your scanner maximum optical resolution) - you can put four 4*5.8 inch prints in one scan pass. = 35 seconds (all start to finish processing).
8*11.7 inches at 300ppi = 16 seconds
4*6 inches at 600ppi = 15 seconds
4*6 inches at 300ppi = 10 seconds

For the first two options, you would separate the individual images from the four-set in Photoshop - takes some time, but the scan time alone would be less than 10 seconds per image on this set-up.

The main thing I noticed is that the scanner hesitated a bit periodically - this happens when data transmission isn't keeping-up with scanner speed. I think this is a USB-2 limitation, and if so with USB-1 the stalling and scanning time would be hugely greater.

For printing the images, you don't need more than 300ppi scanner input resolution with reflective scans, so as you see, I saved a lot of time by scanning at 300 rather than 600. But your choice of resolution depends on what is the maximum size print you will ever want to make from these images. A 4*6 area scanned at 600 ppi will allow you an 8*12 inch print at 300 ppi printing resolution, to give you an idea of the possibilities without resampling (inventing pixels).

BTW, I did a screen grab of the first result, posted here. The left side shows the image in the SilverFast preview, and the right side the 8*11.7 inch scan as it opened in Photoshop CS6 35 seconds later, with the Photoshop image dimensions dialog opened to show the dimensions. What's interesting is not only the resolution quality given the limitations of a paper print - even a very good one - but also the consistency of colour management between SilverFast and Photoshop - and I didn't need to do any work for this. SilverFast automatically uses its own in-built profile for this scanner. I mention this just in case your prints are in colour - it's also a major issue for post-scan image editing time if you need to correct for poorly managed colour, or any non-neutrality of Black and White scans. I also made a B&W scan of this image, at 600 ppi, using the 16-bit scan mode option in SilverFast. The result is completely neutral, also posted here.

So in sum, a range of considerations to take into account regarding speed and efficiency:

-what kind of output do you need, hence what image size and resolution is needed?
-what is the computer processing environment?
-subjective issue: how much time is "too much" to get from pushing the scan button to the final result you want, including post-scan workflow if any.
-what quality of colour management (for both colour and grayscale images) is needed to minimize your post-scan editing time
-then of course whether the scanner and scan software will deliver what you need within these parameters.

[cerebros]

OK, if it scans the prints so you get usable results that's good. You don't say how long it took to scan - I suppose - the whole page of images - or just one image? And what size, and what resolution? What computer set-up are you using? All these things affect scan speed, as does your computer and software. So to benchmark your question, I did a few experiments that may be useful guidance for you. For reflective scans (flatbed of prints - your case) I use an Epson Perfection V750 Pro, connected to my MacPro OSX 10.6.8 by USB 2.0. I use SilverFast Ai8 Studio for scanning - as far as I could tell, not available for your scanner model, but Vuescan will work with your scanner. Anyhow, that's my set-up used for this benchmarking.

Unfortunately I don't have any hard figures on how long the scans took but, bearing in mind there was a fair bit of faffing about and experimenting with some settings in Vuescan to begin with, I got eight images scanned in around two hours, although I think I had the multi-pass scanning setting on in Vuescan which I could probably have taken off (as I'm not sure if it improves things much compared to using it on slides or negatives)

This was one image at a time as so far the album I've scanned from is a mix of snaps from over several years so there's no consistency to the images. This has meant I found I needed to apply the "Restore Fading" colour filter in Vuescan for some of the pictures (in truth I'm not sure if they faded or there was some issue with however they were shot but the results didn't quite look natural).

The scans were at 600dpi and 48-bit mode (and as I said, I think I had the multi-pass scanning enabled)

The main thing I noticed is that the scanner hesitated a bit periodically - this happens when data transmission isn't keeping-up with scanner speed. I think this is a USB-2 limitation, and if so with USB-1 the stalling and scanning time would be hugely greater.

I don't recall noticing any stutter but then the prints I've been scanning in so far aren't particularly big - a lot of the older photos (pre-80s) I saw while flicking through one album appear to be smaller than 6x4, some of those that I think are from the 40s and 50s don't appear to be more than about 4" square

-what kind of output do you need, hence what image size and resolution is needed?

That's kind of the $64,000 question.  So far I've scanned in using the A3 Printed Size option (although I've always been a bit hazy on the purpose of that setting as I'd have thought the printed size would be something the photo package would scale the image for should it be insufficient) from the Output tab in Vuescan but to be honest I'm not sure whether these will actually ever be printed or not, it's more a case of archiving digitally in the best possible quality in case mum's house should burn down and I don't have the prints to go back to.

-what is the computer processing environment?

Computer processing environment is a Lenovo Windows 7 (64bit) laptop, 4GB RAM (will be moving up to 8GB once I've finished giving it a "shake-down"), i5-3210 (2.5Ghz)

For the time being any editing of the images will likely be done in my ancient copy of Photoshop Elements (unless GIMP ever gets decent controls sometime in the near future)

-subjective issue: how much time is "too much" to get from pushing the scan button to the final result you want, including post-scan workflow if any.

Given that I'm purely looking at scanning in right now, so no post-scan workflow to consider, ideally no more than a couple of minutes

[Mark D Segal]

I agree, you can turn off multi-sampling. Your computer should be OK. I think your main issue in terms of scan time is likely to be USB-1. Perhaps an idea to make sure the scanner is warmed-up, you have everything set in Vuescan the way you want it, and start timing from the moment you press the scan button until the scan completes processing. Then you'll know what you are up against and whether it would be worthwhile up-grading the scanner to something compatible with USB-2. Decent flatbed scanners for what you want to do are real cheap these days. By the way, A3 is 11*17 inches. Sounds much too big for your needs. I suggest selecting a smaller output size more commensurate with your eventual intentions.

[BartvanderWolf]

Next question is, what is the best file format to save the scans in?

Hi,

TIFF. When you're finished with postprocessing, high quality JPEGs should not be a problem.

Cheers,
Bart

[Alan Klein]

Do your pictures have cracks and other type mars?  If so, you might want to consider ICE corrective options on more modern scanners.  They will take a lot of those defects out so you don't have to correct in Post Processing.

[cerebros]

By the way, A3 is 11*17 inches. Sounds much too big for your needs. I suggest selecting a smaller output size more commensurate with your eventual intentions.

What does changing that option actually do though?  I'm not clear on the relationship between the output size setting and the actual image resolution and other details as scanned in

[cerebros]

Do your pictures have cracks and other type mars?  If so, you might want to consider ICE corrective options on more modern scanners.  They will take a lot of those defects out so you don't have to correct in Post Processing.

Something to consider.  I don't think the initial photos I'm going be scanning will have as they'll probably have gone straight from the processor's envelope straight into the album but I guess it's a possibility with some of the older ones so I might have to assess that bridge when I come to it and see what my budget can stretch to.

[Mark D Segal]

What does changing that option actually do though?  I'm not clear on the relationship between the output size setting and the actual image resolution and other details as scanned in

The input (the media to be scanned - your photos) has a fixed size. Let us say the long dimension of the typical print is 6 inches for sake of demo. Your scanner has a maximum resolution - defined as pixels per inch - of 600, which for your purposes is OK. If you set it to 600 and you keep the long dimension to 6 inches, you will be scanning-in 3600 total pixels on the long dimension (6 inches times 600 pixels per inch). If however you want a 12 inch long dimension, you will be scanning-in 7200 total pixels. It takes longer to scan-in 7200 pixels than 3600 pixels and the file size will be much larger. But you can make bigger prints at very high resolution. In fact, you don't need that much resolution for your printer. 300 pixels per inch would do fine. No matter what scanning software you use, the higher the pixels per inch you select and the larger the scan dimension (i.e. # of inches of the scanned image), the higher the pixel count, the longer the time for the scanning process and the larger the file. In the scan software, the two things you need to pay attention to are the pixels per inch desired for the scan itself (i.e. the OUTPUT) and the number of inches you want the longest dimension to be.