Publisher 2 : Huge PDF export size

[kamelus]

Hi all
I gave created a photo book of 200 pages, when I export the document in PDF format, the file size is 800 MB which I consider too large. when instead of exporting I use the print to PDF functionality, the generated file is 45 MB without loss of quality. could you please tell me why the export generates such large files? Is there a solution to export smaller PDF files?

 

Thanks for your help

[R C-R]

What settings are you using in the PDF Export window, particularly in the Advanced section, like for allowing JPEG compression?

[kamelus]

25 minutes ago, R C-R said:

What settings are you using in the PDF Export window, particularly in the Advanced section, like for allowing JPEG compression?

Here is th export options 

Thanks

[R C-R]

11 minutes ago, kamelus said:

Here is th export options 

What do you get if you lower the JPEG compression below the maximum of 100, say to 85 or a bit less?

[kamelus]

15 hours ago, R C-R said:

What do you get if you lower the JPEG compression below the maximum of 100, say to 85 or a bit less?

Hi RCR thanks for your answer 

if i choose lower compression to 85 the size of genereted file is 240 Mo  it's less than the initial file but i have to keep the quality at 100% because it's for a photobook impression 

[PaoloT]

1 hour ago, kamelus said:

i have to keep the quality at 100% because it's for a photobook impression 

90 is nearly indistinguishable from 100. It might be a viable compromise.

Paolo

 

[thomaso]

18 hours ago, kamelus said:

when instead of exporting I use the print to PDF functionality, the generated file is 45 MB without loss of quality.

1 hour ago, kamelus said:

i have to keep the quality at 100% because it's for a photobook impression 

Sure? – If you print to PDF you quite likely don't get a PDF/X … and I wonder what JPG compression rate gets used. If it results in 45 MB where you don't notice a loss of quality: What makes you think you would have to keep the quality at 100% ?

You mentioned 200 pages but for an estimation of PDF file size the page respectively the image dimensions / the number of images would be required. What is the file type and total size on disk of all used images? Do they all together come close to 800 MB or rather to 45 MB? Did you edit the images within APub, e.g. by adjustments, filters, blend modes?

What colour profiles are applied to the images on disk? If you don't convert them on export (as shown in your settings) Affinity might embed their profiles in the exported PDF, in worst case for every single image, separately even for identical profiles.

[kamelus]

1 hour ago, PaoloT said:

90 is nearly indistinguishable from 100. It might be a viable compromise.

Paolo

 

Thanks Paolo

 

1 hour ago, thomaso said:

Sure? – If you print to PDF you quite likely don't get a PDF/X … and I wonder what JPG compression rate gets used. If it results in 45 MB where you don't notice a loss of quality: What makes you think you would have to keep the quality at 100% ?

You mentioned 200 pages but for an estimation of PDF file size the page respectively the image dimensions / the number of images would be required. What is the file type and total size on disk of all used images? Do they all together come close to 800 MB or rather to 45 MB? Did you edit the images within APub, e.g. by adjustments, filters, blend modes?

What colour profiles are applied to the images on disk? If you don't convert them on export (as shown in your settings) Affinity might embed their profiles in the exported PDF, in worst case for every single image, separately even for identical profiles.

Hi thomaso 

The file type is Jpeg treated with Affinity Photo the color profil is the CMYK  the total size on disk is 950 Mo  , when i xhoos PDF/X the embed profil color can't be desatviated 

 

And you are right if i choose to export the pdf using the print option instead the export i don't get the PDF/X

Really i don't know if there is a solution or not

 

[thomaso]

2 minutes ago, kamelus said:

The file type is Jpeg treated with Affinity Photo the color profil is the CMYK  the total size on disk is 950 Mo  , when i xhoos PDF/X the embed profil color can't be desatviated 

The option "embed profile" concerns the PDF (its output intent for PDF/X), not the single images.

CMYK for the images is no profile but their colour space. If the images have a different profile than the document or its export it can result in extra profiles (for every image). The fact that you have set for export "CMYK" plus a specific profile indicates that your document doesn't have this setting, which could mean an extra colour conversion + embedded image profiles. – If your document is set to CMYK and this Fogra39 profile there is no need to choose this once more on export but you rather keep both "as document", especially if the images were saved with this profile, too. – If the images have a different profile saved than the export profile then activating the export option "convert images" may reduce the file size by the sum of the otherwise embedded profiles of the images.

Nevertheless, if the images all together have 950 MB on disk + are used in about 100% size + you prefer to maintain 0% compression then 800 MB for the PDF appears like a required consequence … that could get reduced by more compression to result in a smaller file size.

I still wonder what compression you get when printing to PDF with the resulting "45 MB without loss of quality". The fact that this is no PDF/X doesn't influence the PDF size remarkable in this case.

[kamelus]

1 hour ago, thomaso said:

The option "embed profile" concerns the PDF (its output intent for PDF/X), not the single images.

CMYK for the images is no profile but their colour space. If the images have a different profile than the document or its export it can result in extra profiles (for every image). The fact that you have set for export "CMYK" plus a specific profile indicates that your document doesn't have this setting, which could mean an extra colour conversion + embedded image profiles. – If your document is set to CMYK and this Fogra39 profile there is no need to choose this once more on export but you rather keep both "as document", especially if the images were saved with this profile, too. – If the images have a different profile saved than the export profile then activating the export option "convert images" may reduce the file size by the sum of the otherwise embedded profiles of the images.

Nevertheless, if the images all together have 950 MB on disk + are used in about 100% size + you prefer to maintain 0% compression then 800 MB for the PDF appears like a required consequence … that could get reduced by more compression to result in a smaller file size.

I still wonder what compression you get when printing to PDF with the resulting "45 MB without loss of quality". The fact that this is no PDF/X doesn't influence the PDF size remarkable in this case.

Hi Thomaso

All the images have been treated with Affinity photo and the same Color Profil  CMYK

I tried this now : Export With 90% Quality PRofil color same as document  the result : PDF size generated 300 Mo
                            Export With 100% Quality PRofil color same as document  the result : PDF size generated 800 Mo

For me i don't understand why the size difference between 90% quality and 100% is so big 

I forgot , concerning the images i don't use them at 100%size when i exported them with Affinity photo i exported the with this resolution 1200X800

 

Thanks for your Help Thomas

 

[R C-R]

38 minutes ago, kamelus said:

For me i don't understand why the size difference between 90% quality and 100% is so big 

Basically, it is because at the 100 level almost all fine details are preserved during compression, even those that are effectively invisible to the eye, while at lower levels progressively more details are removed. There are many references explaining how JPEG compressions works, for example this one at https://genome.cshlp.org/site/misc/tsg_JPEG_instructions.pdf, or the compression section of the Wikipedia article at https://en.wikipedia.org/wiki/JPEG#JPEG_compression.

[Old Bruce]

21 hours ago, kamelus said:

For me i don't understand why the size difference between 90% quality and 100% is so big 

It really depends on the amount of detail in the image. Lots of fine detail means a huge file size at 100% and a much smaller one at 90%, low detail means the file sizes will be similar, if not the same for extreme examples. These are all the same 8 1/2 x 11 inch size RGB. Note the 90% detail file is less than half the size of the 100% detail file.

[kamelus]

21 hours ago, R C-R said:

Fondamentalement, c'est parce qu'au niveau 100, presque tous les détails fins sont préservés pendant la compression, même ceux qui sont effectivement invisibles à l'œil, tandis qu'aux niveaux inférieurs, de plus en plus de détails sont supprimés. Il existe de nombreuses références expliquant le fonctionnement des compressions JPEG, par exemple celle-ci sur  https://genome.cshlp.org/site/misc/tsg_JPEG_instructions.pdf , ou la section compression de l'article de Wikipedia sur  https://en.wikipedia. org/wiki/JPEG#JPEG_compression .

Thanks RCR 

39 minutes ago, Old Bruce said:

Cela dépend vraiment de la quantité de détails dans l'image. Beaucoup de détails fins signifient une taille de fichier énorme à 100 % et une taille beaucoup plus petite à 90 %, peu de détails signifie que les tailles de fichier seront similaires, voire identiques pour les exemples extrêmes. Ce sont tous les mêmes RVB de taille 8 1/2 x 11 pouces. Notez que le fichier de détails à 90 % fait moins de la moitié de la taille du fichier de détails à 100 %.

Thanks Bruce