How Do The Professionals Scan Stamps?

When I scan a stamp, it's not perfectly straight. If I adjust the image by perhaps half a degree, there's a loss of detail. How do the pros do it?

Use Photoshop, Photoshop Elements or equivalent software. The key is to save the file as a tif or psd (if using Photoshop) instead of a jpeg file. Because of lossy compression, every time a jpg file is edited, it loses image quality.

Doing ANY software based manipulation will introduce a loss of details; including rotating which usually uses a bicubic resampling of the pixels to achieve the rotate. You must scan it straight to start with and avoid EVER using software to manipulate the stamp image at all costs. This means either trial and error or the use of some kind of template to hold the stamp straight. I have looked for scanners platens that have either measurements grids of other alignment markings printed into the platen surface but have not found any.

And as Clark (cfrphoto) indicates, you should never save a stamp using a compressed file format.
Don

Scan your stamp.
Install and use Picasa 3
"Deskew" the image to your requirements ....(lossless *.jpg)

I employ Epson scanners which have "carousel" options,
That way I can individually scan say 40 stamps automatically, then deskew.
Good Luck

rod,
Please note that any software manipulation which skews, rotates, or resizes the scan will result in the loss of detail no matter how you save it.
Don

So I guess my best bet is to get it as straight as I can, scan it in higher resolution than necessary, as .bmp, then rotate it, losing some detail but still clearer than necessary, then resize to produce a thumbnail, perhaps .tif, .psd or .jpg and displaying that as a hyperlink to the higher quality original bitmap.

If the background is black, maybe I can but black construction paper and tape it to the scanner bed, using the edges of it as guidelines. Then scan and see how straight the paper is, and keep nudging until the paper is straight. Then adjust the scan area so I don't waste much time scanning black construction paper. I also noticed many stamps have perforation lines that are not truly parallel to the design frame.

Serious question- How much difference does using jpeg and straightening a stamp really make?


Turks Islands 1889 Scott 55 1p on 2 1/2p red brown close-up
Die A (SG Die I)

Yes, this was scanned @ 1200 using an Epson V600, and the, horrors , it was saved in jpeg and "straightened".

You can see the quality of the scans using this technique at my blogsite, with thousands of examples.

http://bigblue1840-1940.blogspot.com/

I don't disagree with the assertion that one loses some ultimate detail using jpeg and "straightening", but I say it is trivial practically speaking if one begins with a 1200 stamp scan.

Someone,
Professionals would scan at 1200 dpi or better, save the file directly out of the scanner interface without any manipulation. This file would become the 'base' that they would then use for resizing, adding transparent backgrounds, converting it to other formats and usages. Save these 'base' images on a USB stick of burn them to a DVD. If you are going to the time and trouble to scan a stamp, then it is worth doing right. You will find that you often end up going back to the 'base' image for many reason in the future.

Jk,
For a typical user, not that much but a lot depends on the specific jpg format and tool used to save it. JPG compression level is often an option, the more the compression the more detail is lost (the algorithm averages the colored pixels to reduce the file size). Another consideration is that images often get copied and reused several times. Each time another manipulation is done the more details are lost. Consider that an uncompressed image might be 5MB while the same image compressed would be around 300KB; obviously a lot of data is being lost.
Don

Rod:
Picasa is no longer available. Google has switched their efforts to Google Photos. Sign on with your Google account and store you pics.

It is not useful to save an image as a bitmap (.bmp) file because so much space is wasted. Probably the best format is a tiff (.tif) file saved with 48 bit color depth, assuming the scanner has that capability. Unfortunatly jpeg (.jpg) files are generally limited to 24 bits, 8 bits per channel. Editing jpeg files can lead to color degradation.

I don't agree with Don about rotating stamp images. Unless the image is going to be viewed full size, it is safe enough to scan at say 600 DPI, crop and straighten the image. I have yet to see any workable method for straightening the stamp with enough precision without needing a post-scan straightening step. Saving the image optimized (for a computer monitor) will reduce the number of bytes in the image enough that any loss from straightening will not be seen. This is especially true of images for use on ebay where further degradation can be expected as ebay overprosesses the image for various purposes.

For archival use, making and keeping the original scan as a tiff file will allow future use of the image without loss of information. in a different application, I found that 1200 DPI (HD 1080p) images of color slides are better if the original scan is at 3600 DPI. As one poster points out, scanning the original at a higher resolution, making a copy, straightening it and reducing the size to the target size will produce a better image.

However, for many applications this may be too time consuming.

https://goscf.com/t/50620#437306

So what image format and dpi are you looking for for your Canada StampSmarter catalogue?

Since I am only adding 100 pixel thumbnails and large images that do not exceed 450 pixel width, they can be a lower resolution such as 300 dpi. The reason that .jpg format and lower resolution images are often used is that it lowers loading times and storage space. When a site like this forum or Stamp Smarter contains tens of thousands images (Stamp Smarter current has over 25,000 images and while I haven't asked Bobby I am sure that this forum has at least that many ) performance and storage become an issue.

Clark,
I don't think we disagree, the original context was "what do professionals do?" which could be taken a lot of ways. If the original question is read as, "what is the ideal method for scanning a great image" than I stand by my comments. If it is read as, "what is good enough in many/most cases" then yes, manipulation is certainly acceptable.

The issue with color retention and representation is probably more applicable to this discussion then 'details'. Losing pixels really rears its ugly head with colors.

I would also add online images are being impacted with the same issue I outline in the 'responsive websites' in the APS thread. Images should also be 'responsive'. While this is not a direct impact on how a stamp is scanned, there is a significant indirect impact.

Ideally online image will be stored at a much higher resolution so that they can be dynamically responsive and retain the quality. This is accomplished by using a few web code methods as outlined below.

<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0">

<style>
img {
    width: 100%;
    height: auto;
}
</style>
</head>

<body>
<img src="http://stampsmarter.com/Glossary/images/65cZeppelin.jpg">
</body>

</html>

The img style is defined in the header, an meta tag is added to let mobile devices know about it, and then the img is called in the body of the web page as shown above.

This result in a responsive image as seen here http://www.stampsmarter.com/responsiveimage.html Note that as you shrink the webpage in your browser the image will resize dynamically.

This may change the way we all use images in the future and drive us to start using much higher resolution images.
Don

I scan a lot of stamps (every single one in my Dead Country Collection) since I put them into digital albums. I usually scan with a 600 ppi resolution, because the thousands of stamp scans would take up far too much memory on my hard drive. I save the original scan and never manipulate the original image (which is .jpg) so I always have access to the original scan.

Sometimes I put together a special feature which needs a very high resolution scan, and for that I scan at 1200 ppi.

I also straighten most of my individual stamp images before they go into my digital albums, and honestly the loss is irrelevant for my needs. If you look at some of my albums, you can find some poorer images, which are from an older scanner which I no longer have.

One last point, we often mix up the terms ppi and dpi, which are designations for different uses. When we scan an image into a digital format, scanners normally use ppi (pixels per sq in). Technically, dpi (dots per sq in) is primarily for the resolution of the printout of the image. You could scan an image in at 1200 ppi, but if your printer only prints out a 300dpi photo, you will only get 300dpi.

I know some scanners use dpi for scanning, however the designation is because it is normally a scanner/printer, which were primarily designed for scanning an image for printing.

This could be very tiresome for you. (Arghh)
As you can see there are varied requirements for each individual.

I would reiterate, for common everyday usage, for good quality scans
scan at 600 dpi, (Jpeg) hopefully with a carousel optioned scanner (Epson are great)
Tape black art paper to the lid of the scanner.
Bung the stamps on the platen any which way, carousel each stamp, scan in auto, and have a cup of tea whilst it does its work.

Try and pick up Picasa software (Thanks for the heads up this has been discontinued) and straighten your stamps
As jkblue suggests, the loss is neglible

I have in excess of 1 million stamp images, and they work just fine in that format, they load immediately, and I can search for any stamp, within 60 seconds.

There is software out there, that will select 100 or whatever, and deskew automatically.

Good luck if you decide other formats, I'll wager you'll find it a pain, and over the top, for most issues, you can easily flyspec at 600dpi.

Over and out.

I have discovered a feature in the software for my Epson Stylus CX6000 scanner. It's called ZOOM and it is ideal for stamps because it gives a preview image of the smaller area, and the borders of the preview area can be moved toward the perforations to determine how straight the stamp is. The full-bed preview does not provide enough detail, the stamp is too small, but big enough in the Zoom preview.

Now, if the stamp is on there crooked, too far counter-clockwise, that means I have to rotate it counter-clockwise on the bed; because I'm looking down at the bed while the scanner is looking up at the bed. What is clockwise to me is counter-clockwise to the scanner.

What software is used for digital albums? I have about 15K scans of my Israel collection, and I am looking for a way to present them. I was hoping to make an online catalog, where I show not only the stamps, but the FDC's, and other related material for each issue. If there is some tool already available for this, it could save me a lot of effort.