expected instructions file size of PDF (from tools)

[scynox]

hello everyone,

maybe it is a stupid question but I could not find an answer online. neither search forums helped me about an idea.

I am preparing instructions of a technic theme MOC with 2100 pieces total, using Stud.io. actually it is done/complete. problem/question is the file size I get with Stud.io. it is huge.

I created the PDF using Stud.io in 330 pages/530 steps and the output of Stud.io PDF is around 200MB. I checked various PDFs from other modders and I see sizes around 20-50MB in very good image quality while Stud.io PDF quality is only good if 2x or higher is selected but file size is 200MB or higher even then. I looked into PNG compression tools briefly. I exported images from Stud.io, compressed the images myself and made a PDF, still file size is 100MB total. page count is same, image size is 1684x1190, kind of good quality I would say.

am I missing sth about a compression? I tried another tool (lpub) and it generated 200mb file like Stud.io (but open 650 pages of PDF instead). I am not familiar with Lpub so I am not sure if I managed to do it proper way.

what is the expected file size of PDF instructions if a fullsize A4 is used like Stud.io does? is 100MB file size accepted for a 330 page instruction?

thanks

 

[supertruper1988]

I have found that I do not end up using built in PDF exports for my instructions. I export all the images as transparent PNG files that are 300 DPI then I use a program like Adobe Indesign or Affinity Publisher to apply covers and put all the page images on a page then I export from those programs at 150DPI making the files smaller. 

Hope this helps. 

[SylvainLS]

You could also try converting the files to JPG before making the PDF, the loss is minimal and the filesize is generally smaller (at least it is for scanned documents; I don’t make many PDFs).

[Mylenium]

18 hours ago, scynox said:

what is the expected file size of PDF instructions if a fullsize A4 is used like Stud.io does?

Aside from the built-in PDF exports in both LPub and Stud.io being rather shitty, the key point is how the PDF's "objects" are generated. More "editable" objects, more data. It is typically much more efficient to flatten your PDF, either by rasterizing your pages in tools like Acrobat or rendering image-based pages right away and assembling them in a PDF creation tool. Unfortunately even that isn't as simple as it sounds, as the effective file size is determined by the internal encoding of the PDF and what options you use for image embedding. If you have well-optimized PNGs for instance, you would need to set the PDF options in such a way that your images don't get converted to JPEG or even TIFF data inside the PDF. In contrast to @supertruper1988 I'd stay away from transparencies right away in such a case, as having the layout program generate a fill color for the background automatically means that it's re-flattened and the image data may change. As to your specific predicament - it's impossible to judge without understanding your model structure and in turn how the PDF data has been generated. Providing sample PDF pages or at least some screenshots might help to clarify and put this in perspective.

Mylenium

[scynox]

@Mylenium @SylvainLS @supertruper1988

thanks for answers.

currently I am looking into (mass) image processing tools (pngquant and magick works quite fine for now) to convert the images to jpg.

here is a sample page which is over 7MB with Studio 4x but I can compress it to 440 kb in jpg format. I use pdf24 to create PDFs and it generally does not add overhead to PDF size (PDF size is generally less than %2 more compared to total image size). not every page is like that, this is one of the biggest pages in size. most of the pages have multiple smaller steps. still if I have 300 pages total and average is 400kb file size then the total file would be over a 100MB. is that normal? that is my main question in the topic actually.

[Mylenium]

If you're using JPEG, the pin holes and other smaller elements will get in the way. They produce lots of "noise" and reduce the efficiency of the compression because more smaller blocks are being generated. I would definitely try PNG in such a case. Just doing a quick & dirty conversion of your image in PS reduced the file size to 100k and that doesn't even account for the unnecessary noise you introduced via the JPEG compression. Rendering directly to PNG and optimizing this could easily yield half of that size with the added benefit that you could even ramp up the DPI/ dimensions a bit without adverse effects. Getting this to be under 50 MB is absolutely feasible.

Mylenium