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Hi guys,

I would like to understand the process on export and why the exported PDFs are so big.

I just created 16-page brochure meant for electronic use - 2200x1500px. It has total of 9 images which I've downsampled in advance to smaller sizes at 72dpi.

If I choose PDF (digital - high quality) it results into 50MB file.

If I choose PDF (digital - low quality) it results into 40MB file.

In both cases the images are compressed to 85% - I don't want to go lower as this document is meant for developer presentation and they need the pictures to really stand up and be of high quality. The document's resolution is 72dpi.

 

Now here comes the fun part:

The thing is that when I ran both of these files through online PDF Resizer with the setting 'Medium quality (150 dpi images)' I got two files - 5.6MB and 4.6MB - and guess what: I cannot tell the difference! The text looks the same, the pictures look exactly the same.

How on earth is this possible and why Affinity Publisher cannot do this process on its own? 

 

Thanks for your thoughts.

 

 

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4 hours ago, Lagarto said:

Please ensure that youf bitmaps are in 8-bit color format. Otherwise they will probably be included uncompressed.

They're definitely 8 bit images as I never use 16 bit ones anyway. 

The problem must be somewhere else.

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Ok, which version of Publisher (or another Affinity app) do you have? 1.8.2 versions had a bug where images with high placed DPI values would be exported without downsampling and also without JPG compression, and it produced huge PDFs especially when source images were in RGB or CMYK TIFF format. You mention that you have downsampled at 72dpi but if these are large images but placed at small sizes, their placed dpi values can still be high. You can see the placed dpi values and source image sizes in the Resources Manager of Publisher.

If you do have version 1.83 it would be interesting to know some details: e.g. which image format, and which placed dpi values do the source images have. I wonder if this same bug still exists in certain circumstances and causes e.g. accidental upsampling, as this is what seems to happen here. What is the sum total of file sizes if you calculate it from the Resource Manager?

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I just updated Publisher to 1.8.3. But it seems the same to me. 

I've checked the images - the total size is about 23MB. The highest placed dpi value is 143. I have the export PDF (digital - low quality) set to downsample images over 90dpi and JPEG compression to 85.

Still getting a 40MB file. 

1695973836_Screenshot2020-04-05at08_58_47.jpg.4486f344e69fae57be92caab8b039a61.jpg

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OK so I found out what's the problem. It's the 'Convert image colour spaces' command. When I leave this empty I get a file of 6MB.

So there must've been some colour space mess with some of the images I guess. I will have to check and see.

But this solution is OK with me, so thanks for helping me! ;) 

 

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Glad to hear that you managed to resolve this!

However it would be interesting to know what exacly causes this behavior since it seems to be an error in the code. In which color space are your source images? It seems odd that forcing conversion to RGB could cause such an increase in file sizes. One explanation could of course be that the source files were compressed using bigger JPG compression rate than 85 compression rate defined in the export.

But even 6MB sounds big for 9 images forced to be downsampled at 72dpi if the placed DPI value is bigger than 90. If your images are in full page size, this could be but otherwise this still seems large especially if PDF Resizer got them below 5MB using 150dpi. 

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The images are 8bit RGB. 

All the images are between 2000x1500px and 2500x1500px. The largest one in the document is half page but it's in fact full size as the document has a height of 1500px. Only two images are of this size, the other 7 are mostly quarter page images.

I'm perfectly happy with 6MB file but if it were a tad smaller while retaining the same image quality, it would be better, of course. The size always matters. :-)))

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I tested this now with similar size RGB/8-bit images with different export settings, but could not reproduce the problem with "convert image color spaces". However it is clear that PDF (for export) still exports images without downsampling. It just seems that 1.83 version fixed the problem with RGB and CMYK TIFF files which could be huge (and multiple times larger than PDFs created with earlier versions). I had 9 images linked total size of which was around 50MB, and these are the sizes with different Affinity factory default export methods (no changes in export settings):

 filesizes2.jpg.0563158819bbcd60b5ce63fe5c9f6084.jpg

"Custom" file refers to settings that you had used where images were downsampled if placed dpi value was bigger than 90. Generally the placed dpi values of these images was around 700 and the document size was the same as yours.

These are produced with the Windows version. I'll try if there is some difference compared to macOS version (as it seems, because the only export method that produces very large files is "PDF (for export)" -- so I could not reproduce the probem you had). High quality digital version produces also very large PDF's, too large IMO, for a standard export method (300 dpi at 98 JPG compression rate), 200 dpi at JPG 85 would be more appropriate (and produces a bit below 2MB PDF from the same document), but that's a matter of opinion and it is easy to create a custom preset to meet one's own preferences  

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I have now tested this in macOS (Mojave) with version 1.8.3 and the behavior is identical as on Windows.

But as you mentioned that unchecking forced conversion to image color space has effect on the file size, I wonder if the reason for the increased file size is actually in wrong document color format?

doc_colormode.jpg.c61704c52a19f57024eb96f71550d90b.jpg

Choose File > Document Setup > Color and ensure that the document color format is RGB/8. Because if it is RGB/16 or RGB/32, exporting with forced image color space conversion will convert all your 8-bit images to equivalent larger images. As an example, an 9 image album with specs mentioned above, which produces 6 to 10MB PDF with digital high-res default settings would become over 50MB PDF if the document color format is RGB/16.

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You know - this could be it.

I've changed all the settings within this particular file so many times trying to find a problem that I don't longer remember the initial setup. But I just tested it with another file and you are right. 

I will carefully set up some templates in New Document dialog to ensure the settings are right and I don't run into the same situation again.

Anyway - thank you very much for you help and the time! 👍

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You're welcome.

I am not sure if this could actually be regarded as a bug. I cannot see any idea in converting 8-bit images to 16-bit or 32-bit, the other way around it is always meaningful, likewise when converting from RGB to CMYK and vice versa. Anyway, this is how Affinity apps currently seem to behave.

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I'm back to the same problem. I guess I will never understand Color Profiles & Spaces.

Just created a file with 7 pages - the size is 700x500mm, intended as wall presentation.

I've made sure that all the images are linked and manually converted all of them to RGB/8 as some of them were RGB/16.

Yet, when I tried to export as usual for print with my regular settings - see screenshots - I'm getting 350MB file.

I couldn't find a way to find out so I had to create the same file in InDesign and with exactly the same settings I got 99MB file. 

When I tried to export page by page I got 55MB file for the first page in Publisher and 16MB for the same page in ID.

It seems that Publisher forces the command 'Convert Image Colour Spaces' anytime I select PDF/X-1a:2003 - could this be a problem?

 

 

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Screenshot 2020-06-04 at 11.21.37.png

Screenshot 2020-06-04 at 14.14.53.png

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I assume you are back with this problem possibly because of a recent change in APub's export presets, which now by default uses 98% compression quality. (what % is ID using for "Maximum"?)

Just try a page with a lower value to experience a change in PDF file size. Note that Adobe and Serif apps may apply JPG compression differently (different algorhythms), so even "same settings" can cause different compression rate and therefore different file size.

I doubt your assumption that color conversion might influence the file size in that way, if all resources are RGB/8. The color conversion translates color values of pixels, not their compression. Instead, if you do not convert on export, than various resource profiles may become embedded additionally to the documents profile and thereby rather increase the file size compared to non-embedded profiles. (which you will notice with images of much smaller size.)

I don't know if your TIF files get treated differently on Affinity export vs. ID. You also could compare an export (e.g. of a TIF page) with "Rasterise: Everything" to force flattening and possibly re-compression.


macOS 10.14.6, Macbook Pro Retina 15" + Eizo 24", Affinity in Separated Mode (documents merged)

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3 hours ago, brunoczech said:

It seems that Publisher forces the command 'Convert Image Colour Spaces' anytime I select PDF/X-1a:2003 - could this be a problem?

PDF/X-1a;2003 converts images to CMYK and they take more space than RGB images. This shows exactly the same page with 6 RGB JPG images placed on one page and then exported with default PDF/X-1a:2003 and PDF/X-4 export methods:

pdf_sizes.jpg.06a056d6f64093aacc4de80e2fde9257.jpg

So if you have lots of images, or large size images, it could explain at least part of the problem. These standard methods might also use a bit different kinds of compression methods so it may be that the mere change of image color space does not explain all of it. 

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2 hours ago, thomaso said:

I assume you are back with this problem possibly because of a recent change in APub's export presets, which now by default uses 98% compression quality. (what % is ID using for "Maximum"?)

I got nearly the same result with compression set to 95%. ID does not seem to use percentage but with JPEG compression set to Maximum Quality, the resulting size is still 99MB.

 

2 hours ago, thomaso said:

I don't know if your TIF files get treated differently on Affinity export vs. ID. You also could compare an export (e.g. of a TIF page) with "Rasterise: Everything" to force flattening and possibly re-compression.

I got same result with all the images converted to JPEG, too.

 

12 minutes ago, Lagarto said:

PDF/X-1a;2003 converts images to CMYK and they take more spaced than RGB images. This shows exactly the same page with 6 RGB JPG images placed on one page and then exported with default PDF/X-1a:2003 and PDF/X-4 export methods:

Well I guess I'm done with PDF/X-1a:2003 then. :)

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I observed similar problems with large PDF exports and color spaces in Affinity Publisher Windows 1.8.5.

I played around and it seems that there is an image compression problem when the "Document Colour Format" is set to RGB/16 AND the image has to be downsampled to different DPI.

This is what I did: One Image was placed in a document and then exported using the preset "PDF (digital - high quality)". That preset by default downsamples images to 300 DPI, makes JPG with 98% quality and converts image color space, with a setting to Colour Space RGB and ICC profile "sRGB IEC61966-2.1".

Setting 1) The image was placed onto the page and the image had 300 DPI - so no downsampling was required. Then I changed the Option "Colour Format" in "Document Setup - Color", and exported a PDF with the preset "PDF (digital - high quality)". This is the size of the PDF depending on the Colour Format:

  • CMYK: 5924 KB
  • RGB/8: 6461 KB
  • RGB/16: 6461 KB  --> the same size as with other Colour Formats
  • RGB/32: 5924 KB.

Setting 2): the same image made smaller on the document, so it had 600 DPI. Now the image had to be downsampled in the PDF exprort. This are the PDF sizes:

  • CMYK: 1837 KB
  • RGB/8: 1835 KB
  • RGB/16: 8219 KB  --> huge file, even larger than compared to when the image has 300 DPI in the document
  • RGB/32: 1837 KB

Setting 3) the same image made even smaller with a DPI of 900:

  • CMYK: 870 KB
  • RGB/8: 867 KB
  • RGB/16: 4522 KB --> huge file compared to the other Colour Formats
  • RGB/32: 870 KB

Setting 4) the same image again at DPI of 600, like in Setting 2. But this time I changed the JPEG compression settings during the export:

  • RGB/8: no compression - 4292 KB, 98% quality - 1835 KB, 40 % quality - 229 KB
  • RGB/16: 8219 KB in all three JPEG compression settings (!)
  • RGB/32: no compression - 4295 KB, 98 % quality - 1837 KB, 40 % quality - 231 KB

Sorry for the long read. But it is rather obvious: compression of images does not work if the images are downsampled with a document Colour Format of RGB/16.

Is there a chance for this bug to be repaired in an upcoming new version?

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2 hours ago, Sven_M said:

I observed similar problems with large PDF exports and color spaces  (...)  "Document Colour Format" is set to RGB/16
(...) compression of images does not work if the images are downsampled with a document Colour Format of RGB/16.

A 16-bit .afpub export file size issue was reported in a pre 1.8 beta version, where it appeared Affinity ignored on PDF export the compression setting, didn't (re-)compress JPG resources or used zip compression only.


However, would one really want JPG compression on PDF export when working in a 16-bit .afpub ?


macOS 10.14.6, Macbook Pro Retina 15" + Eizo 24", Affinity in Separated Mode (documents merged)

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I had a closer look on this (just using 8-bit images, 16-bit images are known to result in huge PDF export sizes, but are not that crucial because PDF exports typically only include 8-bit images).

These are PDF exports from InDesign and Affinity Publisher using default settings for PDF-X1a:2001(3) and PDF-X4, the former converting images to CMYK and the latter keeping them as RGB. The document format was 50 x 70cm containing 6 pages of paintings sources of which were linked RGB JPG filles with varying resolutions (for a poster basically 150 placed PPI value is enough, a bit depending on the viewing distance and the kind of an image, so here some images are a clearly low-res, and some a bit too high-res, but resolutions are typical enough to give a realistic picture of the sizes of PDF exports this kind of a document is likely to produce).

pdf_sizes_compared.jpg.5673c480c83e7ae1482a9166c4ecb90d.jpg

It can be seen that Affinity Publisher creates significantly bigger PDF exports than InDesign, both when exporting with PDF-X1 method (CMYK images) and PDF-X4 method (RGB images).

The file sizes of the original linked files were as follows:

pdf_origsizes.jpg.ef423a9eda7cab485a5689bf0e1db035.jpg

When opening these files in Publisher and viewing the file sizes in Resource Manager, following is shown:

pdfx1_apub.jpg.f3f1304bbb857779a68497a003a4fb9d.jpg 

pdfx1_id.jpg.ff5567439f60275f24fee5bc20c09915.jpg

pdfx4_apub.jpg.8945d3094b057c51569c47601246da47.jpg

pdfx4_id.jpg.e4d0fb55de0cc6542b695ea1ca215ff0.jpg

It is clear that compression done by InDesign is much more effective. As mentioned, these files have been produced with default values, which for InDesign means "Maximum JPG" quality downsampling to 300dpi for images above 450dpi (so no downsampling was performed for the test images), and for Affinity Publisher "JPG quality 98" downsampling 300dpi for images above 375dpi (so no downsampling in this case). 

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Hi guys,

I've got another bug - I guess.

Two pages within one file - exactly the same. Only on the second one the background picture layer has opacity lowered to 15%.

First page has 2.27MB on PDF Export and the second page has 21.92MB !!!

Same settings on export, of course.

Once I leave the background picture as it is and create a white layer on top of it and lower its opacity to 85% to get the same result, the exported file goes down to 2.24MB.

How can one layer's opacity affect the size on export this much I have no idea...

 

 

Screenshot 2020-06-15 at 16.43.24.png

Screenshot 2020-06-15 at 16.43.36.png

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On 4/6/2020 at 6:58 AM, Lagarto said:

I have now tested this in macOS (Mojave) with version 1.8.3 and the behavior is identical as on Windows.

But as you mentioned that unchecking forced conversion to image color space has effect on the file size, I wonder if the reason for the increased file size is actually in wrong document color format?

doc_colormode.jpg.c61704c52a19f57024eb96f71550d90b.jpg

Choose File > Document Setup > Color and ensure that the document color format is RGB/8. Because if it is RGB/16 or RGB/32, exporting with forced image color space conversion will convert all your 8-bit images to equivalent larger images. As an example, an 9 image album with specs mentioned above, which produces 6 to 10MB PDF with digital high-res default settings would become over 50MB PDF if the document color format is RGB/16.

This worked for me too - pulling my hair out and can now let it grow - thank you!!

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I work on a CMYK file (document setting) and cannot upload the exported PDF to the printer, it's just unreasonably huge. Affinity Publisher exports a 300MB file for a 44 page brochure. I once managed to get it to 130MB somehow but now cannot find the right settings anymore. I use PDF-X1a:2001(3) with color conversion to CMYK. The images themselves in "raw" format are in total less heavy and are placed smaller in the PDF. This must be a bug.

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