Poor Quality Scanned Images ME

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Poor Quality Scanned Images ME

This topic has 11 replies, 5 voices, and was last updated 1 March 2010 at 07:34 by David Clark 13.

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28 February 2010 at 16:34 #49290
Terryd
Participant
@terryd72465
The latest ‘Article Reprints’ show the problems involved with scanning printed images. The Frank Whittle articles have reasonably good quality images but the ME scans for the G H Thomas series of articles have extremely poor images. This means that the images are almost illegible. Of course images are important to the articles, after all ‘a picture is worth a thousand words’.

The problem is the moire effect caused by the different resolutions of the halftone image to be scanned and that of the scan. These need to match to remove the effect. You can also use the ‘descreen’ function in modern scanning software which will remove or at least reduce this. I don’t know who is scanning these but really they need to be re-scanned by someone who knows how to overcome these problems. Otherwise the effort is wasted as the articles are of little use for practical modelling or construction.

I wouldn’t expect perfection but I think we need at least competently scanned images in the articles.
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28 February 2010 at 16:34 #39099
Terryd
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@terryd72465
28 February 2010 at 17:18 #49292
Gone Away
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@goneaway
Posted by Terryd on 28/02/2010 16:34:59:

The problem is the moire effect caused by the different resolutions of the halftone image to be scanned and that of the scan.

This issue was raised a while back in respect of the MEW scans:

http://www.model-engineer.co.uk/forums/postings.asp?th=35337

A number of these have been re-scanned but it hasn’t improved the situation much in many cases. I agree – it needs someone who knows what they are doing (and with the right software).
28 February 2010 at 19:38 #49296
Tom Wightman 1
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@tomwightman1
I’d just like to second (or third?) that. I appreciate very much the material being made available, and the work that goes into preparing it (scanning etc.), but the quality is often a bit less than adequate. I notice that the recent issues that have been uploaded that include the “Minnie” series of articles have each been prepared as a single file, which I think is a first. But the file size has been reduced to about 5 MB, and the quality has suffered in consequence. In particular many of the drawings are at least partly illegible – particularly some of the dimensions. I don’t know if this is to encourage people to buy the drawings from My Hobby Store or not, but of course the problem extends to other smaller articles, with drawings that are not available any more, and these articles then become useless.

On a different but related issue, I know that a number of people have raised the issue of making the archives available as pdf files rather than as the cute, but inefficient, FlexiPage presentation, and about the illogicallity of using security from pirates as an excuse for not wanting to do this. But one issue which I believe has not been raised before, is the ability of the pdf format to include an OCR layer “underneath” the graphic image presentation of the document. This makes the entire document (archive) much more useful by virtue of its ability to be searched for key words and phrases. It seems to me that many of the magazines that provide digital subscriptions have taken this route, and it adds enormously to the value of the collection. I don’t believe that mentioning this will make any difference of itself, since the “powers that be” seem to be pretty firm on this issue, but I think it is useful that we all have a complete picture of the benefits and drawbacks of the different technologies.

Tom
28 February 2010 at 22:32 #49300
Gone Away
Participant
@goneaway
Posted by Tom Wightman on 28/02/2010 19:38:53:

I’d just like to second (or third?) that. I appreciate very much the material being made available, and the work that goes into preparing it (scanning etc.), but the quality is often a bit less than adequate.

It might be appropriate to add that, while one can be at least somewhat tolerant of the lack of quality in the items provided free of charge, it’s much harder to feel that way in respect of the archive issues for which a subscription is paid.
28 February 2010 at 22:50 #49302
Terryd
Participant
@terryd72465
Posted by Sid Herbage on 28/02/2010 22:32:03:

Posted by Tom Wightman on 28/02/2010 19:38:53:

I’d just like to second (or third?) that. I appreciate very much the material being made available, and the work that goes into preparing it (scanning etc.), but the quality is often a bit less than adequate.

It might be appropriate to add that, while one can be at least somewhat tolerant of the lack of quality in the items provided free of charge, it’s much harder to feel that way in respect of the archive issues for which a subscription is paid.

Even With free stuff Sid, it is just as easy to produce quality documents as to produce useless ones. Compare the Eric Whittle articles with the G H Tomas articles in ‘reprint articles’ and see what I mean. One could use the Whittle article to produce a product whereas the images in the latter (Thomas’s) are just about worthless and a waste of time, and effort for that matter.

My apprentice trainer always taught us to do things properly and then it only has to be done once. I’m sure that we have all heard that one, but the advice it seems. is not always followed.
28 February 2010 at 22:56 #49303
Terryd
Participant
@terryd72465
By the way, just a bit of advice on scanning, but I’m probably teaching granny to suck eggs so forgive me if this is obvious:

If anyone is scanning magazine articles etc for their own use. Do not scan as ‘photograph’ or however your software terms it. Scan it as a ‘document’ (whether colour or black and white). Pictures in magazines are not photographs but halftone images and by defining it as a ‘document’, the software will try to make some compensation for that fact and will reduce the moire effect which has ruined some of the scans here.
28 February 2010 at 23:55 #49304
Tom Wightman 1
Participant
@tomwightman1
Posted by Terryd on 28/02/2010 22:56:49:

If anyone is scanning magazine articles etc for their own use. Do not scan as ‘photograph’ or however your software terms it. Scan it as a ‘document’ (whether colour or black and white). Pictures in magazines are not photographs but halftone images and by defining it as a ‘document’, the software will try to make some compensation for that fact and will reduce the moire effect which has ruined some of the scans here.

Well, I think you have to be careful on that one Terryd. The important thing is that the software use its descreening filter, set to an appropriate dpi value (based on halftone screen pitch). Different software will likely have different interpretations of when that capability should be made available, depending on what they mean by “Document” etc. Currently I mostly use VueScan, which does not even have a setting called “Document”. It does, however, have settings for “Magazine” and “Newspaper”, both of which will invoke the descreening filter, at preset values assumed typical for each of those two input media. But the best results are likely to be had by measuring the screen pitch on the material you are scanning, and setting the dpi value for the descreening filter manually.

Tom
1 March 2010 at 00:15 #49305
Richmond
Participant
@richmond
Gents,

The articles published on the website fall into 2 categories. Those produced for digital reproduction ( MEW / ME digital archives ), and those that are published for free, or as part of the subscription article series.

Neither David or I have any control over the first category … but I am sure that your comments will be passed on.

As for the articles eg, Minnie and G H Thomas, well…. the amount of time allocated to maintaining the website dictates that sometimes we have to use scanned images from sometime ago, as opposed to re-scanning articles freshly. To reproduce the “Minnie” article from afresh, in terms of producing 11 magazines re-scanned to suit your requirements would mean an inordinate amount of time allocated, and hence a much higher cost. Further there are 41 magazines in the series…. to be published over the next for weeks. Rescanning is NOT a practical prospect,

The articles are not meant to replace proper printed magazines, or books. They are provided purely as reference material. Having checked most of them myself in my PC I feel that for the effort spent they are legible, and the drawings can be read. If you require the proper full size drawings they can be purchased on the website. The web traffic on the site is phenomenal, and hence PDF sizes also have to be cut down, this also reduces quality.

Whilst I appreciate your comments, we are doing our best with limited resources to provide you the members with material ( mainly for free as well ) that is popular as well as relevant. We do strive to do better. However, in this economic climate I feel certain that no additional time or resources will be put into rescanning articles.

Regards

Keith

Edited By Richmond on 01/03/2010 00:21:47
1 March 2010 at 00:50 #49306
Tom Wightman 1
Participant
@tomwightman1
Very fair comments Keith. I assume, like myself, other subscribers were not aware of the use of pre-existing scans in some cases. Certainly it would be difficult to justify redoing them when there are copies already in existence.

Keep up the good work and don’t let our moans get you down

Tom
1 March 2010 at 07:16 #49307
Terryd
Participant
@terryd72465
Well, I think you have to be careful on that one Terryd. The important thing is that the software use its descreening filter, set to an appropriate dpi value (based on halftone screen pitch). Different software will likely have different interpretations of when that capability should be made available, depending on what they mean by “Document” etc. Currently I mostly use VueScan, which does not even have a setting called “Document”. It does, however, have settings for “Magazine” and “Newspaper”, both of which will invoke the descreening filter, at preset values assumed typical for each of those two input media. But the best results are likely to be had by measuring the screen pitch on the material you are scanning, and setting the dpi value for the descreening filter manually.

Tom

I quite agree Tom, I was just trying to make a simple piece of advice available and I did make the caveat that there would be some differences between softwares and I do fully agree with your final recommendation of actually counting the screen pitch for best results. And of course if you are scanning consistently printed magazines then you only need to do the process once.

Keith you have made fair comment. The problem is not with the drawings and captions etc but with the accompanying images which are used to explain difficult points, it is those that are illegible. I do know how long it takes to scan publications I have done a great deal myself. Try scanning and then ‘repairing’ damaged pages one by one, That does take time.
1 March 2010 at 07:34 #49308
David Clark 13
Participant
@davidclark13
Hi There

The articles put up for free where scanned by a Model Engineer for his own use.

He kindly gave me his entire collection on memory cards to upload.

The possibility of recanning these is not on.

Firstly, the time.

It took me nine hours to completely scan MEW issue no 1 properly.

That is clearly not on.

We have archives of original magazines which we have used for digital editions which are mostly taken from original Quark Express and InDesign PDFs.

These are of a much higher quality.

regards david
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