Author Topic: Compression method of pictures  (Read 1680 times)

founder

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Compression method of pictures
« on: April 27, 2012, 11:49:51 am »
Just right now, at export PDF, there is to choose

Automatic
JPG
ZIP
None

This seting has a extreme influence on the size of the generated PDF
All tested set to 200 dpi.

Auto - high -------- 57332 kb
Auto - medium ---- 56851 kb
jpg - high ---------- 10118 kb
jpg - medium ------  8378 kb

So I can make the PDF version for distribution only with JPG compression
This is not optimal for graphics.

I think the methods for "automatic" should be worked over.
All what's imported from a PNG should be compressed looseles.
All what's imported as a JPG should be compressed loosey.

Sometime's, it happens that a PNG graphic shrinked to a smaller size has more  kb than the original.

So the decision should be:

Shrink graphic to dpi
Compare size with original
Use original graphic if size is smaller or equal

Nermander

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Re: Compression method of pictures
« Reply #1 on: April 29, 2012, 04:30:19 pm »
I guess the major question here is: What image compressions are allowed in a PDF?

I guess this page gives a hint on what formats are possible to use.
http://en.wikipedia.org/wiki/Portable_Document_Format#Raster_images

Scribus main target is printing, when printing the print quality is more important than file size, that's probably why the automatic setting gives big files.

 

palmate