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Re: Cleaning a grayscale score?

Posted: Fri Jun 17, 2011 10:16 am
by carmar1791
I have just upload file I got by scan tailor (B&W),so you can see what scantailor do by default (I completed missing lines and notes only by gimp)
Better results can be obtained manually , by setting brightness and contrast on a grayscale image (gimp), or by setting grayscale image in scantailor.
But with a grayscale image you will have abigger file, may be bigger than your colour pdf (because dpi resolution is higher)
You could produce and uplopad a grayscale file so you could see yourself to to which extent you can better image.
Greetings

Re: Cleaning a grayscale score?

Posted: Fri Jun 17, 2011 3:04 pm
by WilliamBunting
Dear Crmar 1791 and Kalliwoda

Thank you for the beautiful Hofmann results.

I'm sorry I seem to be deliberately ignoring your advice. Unfortunately I don't understand half of it. I'm a raw beginner at this work, having made my first ever pdf file two weeks ago.

For example nowhere in my sw do I get information on the resolution. On a bmp file "property" tells me it's 300 k and 1419 by 1733 pixels. My gimp is 149k, the final mono pdf 47k and the initial greyscale pdf 300k. How do I find the resolution and where do I do the split point adjustment?


Regards and thanks

WB

Re: Cleaning a grayscale score?

Posted: Fri Jun 17, 2011 3:36 pm
by kalliwoda
William,

Photoshop displays dpi, but this is just calculated from the 1419x1733 pixel resolution and the page dimensions (If its 30 cm or about 12 inch for the vertical, you get a bit less than 150 dpi, about 125 dpi if its 35 cm/14 inch). Since I have no experience with gimp, I cannot advise on how to increase dpi, but essentially you should be able to double pixels and leaving dimensions the same.

The splitpoint option may be somewhat hidden, took me a while until I found it under "Schwellenwert" in my german version of Photoshop 7.

Try ScanTailor, its Freeware! runs under windows, and I just discovered it is now also available for Mac OS-X :)

Re: Cleaning a grayscale score?

Posted: Sat Jun 18, 2011 9:41 am
by carmar1791
WilliamBunting wrote:Dear Crmar 1791 and Kalliwoda

Thank you for the beautiful Hofmann results.

I'm sorry I seem to be deliberately ignoring your advice. Unfortunately I don't understand half of it. I'm a raw beginner at this work, having made my first ever pdf file two weeks ago.

For example nowhere in my sw do I get information on the resolution. On a bmp file "property" tells me it's 300 k and 1419 by 1733 pixels. My gimp is 149k, the final mono pdf 47k and the initial greyscale pdf 300k. How do I find the resolution and where do I do the split point adjustment?


Regards and thanks

WB
If you open an image
In gimp you find it in Image>Property or Image>Print-Size

If you import a file (from pdf etc) in gimp or any other programs, choose in the first window allways at least 600x600 dpi or more if you want.

In scantailor too:at beginning there is a window it ask you how many dpi you prefer.

"where do I do the split point adjustment?" Gimp: before converting image , use threshold! (or may be levels ) : Colors>Threshold ... and you will find a window to set white and black cursors in the better way. (the default values are those gimp use for automatic conversion (split point of 50%)
If you choose to use levels (Colors>Levels) the result can be the same, you will have one or two cursors more, but before converting file, remember to merge down levels and remove alpha channel: Layer>Merge down and Layer>Transparency>Remove alpha channel.

After appling threshold (or level) go to Image>Mode>indexed etc...

By the way remember this:The split point adjustment (threshold) works fine if you have a quite good image. (Hoffman is quite good so you could do in this way).
If image is worst (lower resolution), your only chance is keeping image in grayscale mode, and adjusting contrast-brightness (and-or appling some tricks like gaussian blur etc etc).....

Greetings