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Reducing PDF Size - Loss of resolution on Logos Only

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#1
The Mad Mapper

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Hello All,

I am at a loss here, and need some help. I have my fingers crossed that someone will have seen this problem before and will be able to help!

I produce maps using ArcMap (I have ArcView v10 ). I usually provide clients with pdf copies. My workflow has been to export from ArcMap to pdf. The resulting pdf file is usually quite big, so I use the "Reduce File Size" tool in Adobe Acrobat to reduce the file size. It works great, often reduce the file size by 4/5 and keeping really good resolution.

The problem is that I just noticed that the logos that are part of the map loose a lot of quality when I use "reduce file size" to reduce the file size. Indeed, it seems that all vector data is well preserved while "raster" data looses it's crispness.

see attachement ( after using the "reduce file size " option- I could not upload the before view, as it was too large- but you can take my word for it, the logos are "crisp". The other option to reduce file size that I know of is to use the save-as method, however this method does not compress the pdf as much.

I am hoping that someone out there has some insight!

Any suggestion, (or words of encouragement) are welcome!!!!

The Mad Mapper

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#2
razornole

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My guess would be that it has to do with your document raster effect settings (in Illy: Effects-Document Raster Effects Setting). I rarely use acrobat, but I have had a similar problem in Illustrator. Turns out that the default settings for rasters in Illy is set to 72dpi. I'm sure that there is some type of similar setting in acrobat. For print I would set it to 300dpi, viewing on a computer 150dpi.

If that doesn't work I would look around for imbedded or linked file settings.

Hope that helps,
kru
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#3
woneil

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One trick that sometimes can be surprisingly effective in reducing the size of PDFs of raster graphics is to use Photoshop to change them to indexed color, especially if you can limit the color palette without doing too much damage. I have not needed to do this with mixed vector and raster images, but I suspect that there is a way.
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#4
Matthew Hampton

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"Reduce file size" subsamples rasters to a low (fixed) dpi. If you have AcrobatPro you can tweak the adjustment to your desired outcome.

I would ask your client for vector logos (convert them to .emf for placement in Arc). :)

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#5
Richard

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I often send PDF's created from dwg's that include Logos. I have the logos of the clients I'm working for.
I have Bluebeam PDF, and like said here I set my rasters to 250 or 300 dpi. Default 72 is hopeless.

Sometimes I add the logo to the PDF as opposed to print to pdf from the dwg. Would that help your case?

Either way I have quite small file sizes and very crisp neat logos.
Thats on vector files and no other included rasters.

#6
bramapic

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I guess you are using Acrobat (not Reader) since the Reduce File Size option isn't part of Adobe Reader (correct me if I'm wrong).

As Matthew Hampton said, the easiest way is to always use vector logos. When a client doesn't have a vector version you can try tracing it yourself (Illy) or search it online. You can find a lot of logos in eps-format on Brands of the world.

When raster versions are your only option you can try adjusting the downsample quality of images in the PDF Optimizer in Acrobat. (Advanced>PDF Optimizer).

However the logos on your PDF look like an upscaled poor quality web version or external reference with a missing link.

What is the resolution of these logos?

#7
mfarmer

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Try printing to PDF rather than exporting. PrimoPDF is free and should be good enough.

#8
crowlands

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Hello All,

I am at a loss here, and need some help. I have my fingers crossed that someone will have seen this problem before and will be able to help!

I produce maps using ArcMap (I have ArcView v10 ). I usually provide clients with pdf copies. My workflow has been to export from ArcMap to pdf. The resulting pdf file is usually quite big, so I use the "Reduce File Size" tool in Adobe Acrobat to reduce the file size. It works great, often reduce the file size by 4/5 and keeping really good resolution.

The problem is that I just noticed that the logos that are part of the map loose a lot of quality when I use "reduce file size" to reduce the file size. Indeed, it seems that all vector data is well preserved while "raster" data looses it's crispness.

see attachement ( after using the "reduce file size " option- I could not upload the before view, as it was too large- but you can take my word for it, the logos are "crisp". The other option to reduce file size that I know of is to use the save-as method, however this method does not compress the pdf as much.

I am hoping that someone out there has some insight!

Any suggestion, (or words of encouragement) are welcome!!!!

The Mad Mapper



As what others said it should be created into vector file... corel, Illustrator and save as PDF.. PDF file will reduced without loosing the quality.

#9
M.Denil

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I would agree that vector logos are best, but very, very seldom to be found. Most companies supply absolute trash for their logos, and then wonder why it looks so bad. Vectorizing the logos can sometimes be done, but anything complex is a real chore and are you being paid for that sort of drudge work? Plus, if the customer dislikes the vectorized logo then it really is your fault...

Using any automatic "reduce file size" option is just looking for trouble. They generally resample everything to a single (lower) resolution and snap all raster cells together (which does strange and gastly things to logos). In any event, PDF is notorious for buggering files.

Your practice of using EPS is very wise and proper. PDF offers portability and that is all: if you want quality graphics, AVOID USING PDF IF YOU CAN.

I suggest manually flattening all imagry (including any transparancy and masks and logos) to a single image layer underlaying all evctor layers. This way you are controling (and approving) the raster overlay process rather than allowing the software to do it willy-nilly. Of course, you cannot make changes so easily after that, which is why you preserve the un-flattened version too: the flattened one just goes to print.

Mark Denil




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