Problem with scanner - blurred portions of image

[Perene]

I have a scanner (also printer) here, called Epson XP-204. It has been used for years and many scans. Recently I noticed, while using Adobe Photoshop 2015 (this problem also occurs in the Epson app for Windows 10-64) that some parts of the image were blurred, opaque.

This is the image:
https://goo.gl/xaP3Oj

I tried re-scanning it, this time inverting the page of the book, so as to see if other portions of the mirror (from the scanner) were affected. If not, then I would know this is from the book itself:

https://goo.gl/cayJLv

As you can see by comparing the two images, the 2nd one is clear in that are where you can read: 7. UNITAU, meaning that it is indeed a flaw in the scanning process, I am saying that the scanner isn't working properly as it should, creating this blur.

In both scenarios I scanned at 600 DPI.

The question is: can this be fixed or I'll only solve my problem buying a new scanner?

 

[Solandri]

Judging from the shadows on the edges of your page, the lid of the scanner is not holding the paper flat against the glass. It's been warped somehow; maybe the foam has been crushed in places? The paper rises up from the glass in some areas, and is out of the focus zone of the scanner's optics.

Scanner sensors are actually just a single line of photoreceptors. It's dragged across your page to make a complete 2D scan. So any problems with the scanner's optics show up as vertical streaks. Your blotches are not uniformly vertical. So probably the glass just needs cleaning, or has been scratched in places.

Also, to reduce or eliminate text on the back of the page from showing in your scans, put a black sheet of construction paper on top of the page. That will make the background a uniform black, making the letters on the back side invisible.

 

[kittle]

After displaying the images at 1:1 scale it looks fine to me. Nice and crisp and not blurry

It does look like there is some bleed-through where the scanner is picking up words from other pages in the book.

how is this blurry text causing you problems?

 

[Perene]

Judging from the shadows on the edges of your page, the lid of the scanner is not holding the paper flat against the glass. It's been warped somehow; maybe the foam has been crushed in places? The paper rises up from the glass in some areas, and is out of the focus zone of the scanner's optics.

Scanner sensors are actually just a single line of photoreceptors. It's dragged across your page to make a complete 2D scan. So any problems with the scanner's optics show up as vertical streaks. Your blotches are not uniformly vertical. So probably the glass just needs cleaning, or has been scratched in places.

Also, to reduce or eliminate text on the back of the page from showing in your scans, put a black sheet of construction paper on top of the page. That will make the background a uniform black, making the letters on the back side invisible.

This is how the pages are in this scanner:
https://goo.gl/Gn3agx

As you can see, in this case there's not a chance the page isn't properly aligned, as in "we need to put some weight above the scanner for the page to settle down and be attached with the scanner mirror".

As for the blurring, check this:
https://goo.gl/ZDldBr

It was scanned at 600 DPI by the Epson SCAN app. So this time I haven't used Photoshop (and took 60 instead of 104 seconds), and I am using the automatic settings, saving as JPG in the best quality. You can see in the picture that certain portions of the image aren't crisp like others.

I don't know what is causing this, but I can definitely tell you guys there is a blurring and it is only happening now, it wasn't like that before. That I am dead sure, also judging from the physical book pages.

 

[Solandri]

As you can see, in this case there's not a chance the page isn't properly aligned, as in "we need to put some weight above the scanner for the page to settle down and be attached with the scanner mirror".

If that were true, there would not be any shadows around the edges of the paper in your scans. But there clearly are shadows. This is telling you the paper is not sitting flush against the glass, and you "need to put some weight above the scanner for the page to settle down."

In your last picture, if you look at the edge of the paper under the page number "138", you can see it's curved and the shadow disappears. This indicates the paper has lifted slightly off the glass and is sticking to the scanner lid instead of the glass. And that corresponds exactly to where the text is blurry.

Edit: Looking at the picture of your scanner, it's hard to tell but it looks like the right side hinge for the lid is missing a plastic spacer which is present on the left side. This is probably causing the lid not to lay flat against the glass. The paper gets sucked up against the lid in some places by static, resulting in blurry regions. Places where the paper stays flat against the glass remain sharp.

 

[Perene]

Well, it seems you were right, but that was the 1st time ever something like this occured to me. I never had to put any weight above the scanner like you see here:

https://goo.gl/8u90cd

However, that was necessary for the image to get rid of this problem. Compare the two images:
https://goo.gl/19Bwb2

I said that was unnecessary because I didn't see how the page wasn't properly placed aganst the glass. At least I couldn't see how it wasn't that way, judging from how it laid against the glass without any sign of lifting itself up.

 

[Rocky Bennett]

After displaying the images at 1:1 scale it looks fine to me. Nice and crisp and not blurry

It does look like there is some bleed-through where the scanner is picking up words from other pages in the book.

how is this blurry text causing you problems?

I agree. On my system I actually printed these and they look great.

 

[Perene]

I agree. On my system I actually printed these and they look great.

Actually the blurring is very subtle, but very noticeable only if you put it in max zoom. The letters indeed looked blurry, and that would be fatal if you were planning to use an app such as ABBYY FineReader 12 to do your OCR. At least you could guarantee some minor OCR error while reading these areas. And ABBYY always said my scans (at 300 DPI) weren't clear enough, that's why I decided to scan books at 600 DPI. It takes a lot more time, but I only needed to do this for a few.

I scan books at 600 DPI either using the EPSON SCAN app (in this case, saving as JPG) or Photoshop (BMP, +- 100 MB/file). Then I save it as JPG, with minor loss. Only after this I save a smaller version in PDF (300 DPI), so it will be a PDF with-images, not OCR. The OCR is created from the JPGs with minor loss, but that combined can waste more than 1 GB sometimes.