MobileRead Forums - View Single Post - Drastic pdf drop in quality of scanned book after using acrobat optimize feature

harryE123 · 12-31-2008, 10:40 PM

Happy new year guys, thanks dd, for the replies, I got to tell you man, this is such hard work, I ll start reading an acrobat "bible" book because I am not happy with any of the results so far:

1. some books lend themselves to ocr better of course as anyone might imagine due to them carrying little graphs and pictures, but even these though they gain tremendously, as pdurrant mentioned above, in size I get "funny" fonts there too, most of the text is recognized ok, that is about roughly 97% or more, but the characters get a weird spacing such as this: "t his is a s a mple", of course the spacing isn't as pronounced in being erroneous but it's close.

2. When I apply optimization afterwards I get very weird results too, I try edge shadow removal (agressive) but it almost doesn't work at all, as far as I can tell none of the long solid slim black lines in the margins are recognised as such and removed and if I set the default settings to it I get a LARGER file after the optimization to an ocr book of about 200 pages (with ocr choice 3, not the bitmaps). How can that be. I 'll take your advice dd, and try the "Advanced optimization" but at the moment I struggle to find how this complements, surpasses or corresponds to the simple optimization.

3. With some books with a lot of pictures and graphs ocr type 3 choice is simply unacceptable.

4. One of my original queries still holds and is still very perplexing how by simply applying ocr type I or II I get a degraded quality, should just a sublayer be added, thus more size, but same quality bitmap, why do I get LESS quality there, and less size, it's not supposed to do anything on top of the bitmaps just adding the text sublayer...very strange.

5. The only thing (sigh...) that puts a smile on my face is applying the size reduction by making it compatible to acrobat 8 and above, which it figures just subtracts some levels of compatibility and gains in size which are adequate. This works well so far, no problems.

6. it's very confusing because there are so many things you gotta factor in one of them being the initial choice for quality when merging the original jpgs, should I aim for the highest then work my way down through the various optimizations and ocrs, or should I opt for the middle way, the second choice...

I didn't expect this whole process to be so hard and counter intuitive esp. with such an expensive product as acrobat...oh well...computers...I am computer scientist I should have expected that...

HAPPY NEW YEAR TO ALL, HAPPY READING, BEST OF HEALTH TO YOU AND YOUR LOVED ONES.

12-31-2008, 10:40 PM	#6
harryE123 Banned Posts: 272 Karma: 70 Join Date: Dec 2008 Device: irex reader	Happy new year guys, thanks dd, for the replies, I got to tell you man, this is such hard work, I ll start reading an acrobat "bible" book because I am not happy with any of the results so far: 1. some books lend themselves to ocr better of course as anyone might imagine due to them carrying little graphs and pictures, but even these though they gain tremendously, as pdurrant mentioned above, in size I get "funny" fonts there too, most of the text is recognized ok, that is about roughly 97% or more, but the characters get a weird spacing such as this: "t his is a s a mple", of course the spacing isn't as pronounced in being erroneous but it's close. 2. When I apply optimization afterwards I get very weird results too, I try edge shadow removal (agressive) but it almost doesn't work at all, as far as I can tell none of the long solid slim black lines in the margins are recognised as such and removed and if I set the default settings to it I get a LARGER file after the optimization to an ocr book of about 200 pages (with ocr choice 3, not the bitmaps). How can that be. I 'll take your advice dd, and try the "Advanced optimization" but at the moment I struggle to find how this complements, surpasses or corresponds to the simple optimization. 3. With some books with a lot of pictures and graphs ocr type 3 choice is simply unacceptable. 4. One of my original queries still holds and is still very perplexing how by simply applying ocr type I or II I get a degraded quality, should just a sublayer be added, thus more size, but same quality bitmap, why do I get LESS quality there, and less size, it's not supposed to do anything on top of the bitmaps just adding the text sublayer...very strange. 5. The only thing (sigh...) that puts a smile on my face is applying the size reduction by making it compatible to acrobat 8 and above, which it figures just subtracts some levels of compatibility and gains in size which are adequate. This works well so far, no problems. 6. it's very confusing because there are so many things you gotta factor in one of them being the initial choice for quality when merging the original jpgs, should I aim for the highest then work my way down through the various optimizations and ocrs, or should I opt for the middle way, the second choice... I didn't expect this whole process to be so hard and counter intuitive esp. with such an expensive product as acrobat...oh well...computers...I am computer scientist I should have expected that... HAPPY NEW YEAR TO ALL, HAPPY READING, BEST OF HEALTH TO YOU AND YOUR LOVED ONES. Last edited by harryE123; 12-31-2008 at 10:54 PM.