[I had to repost, I always mix up the save and submit button. So I clicked save and closed the browser]

I have worked with filters and it creates huge PDF files like 15 meg or more. One way to reduce the file size could be to lower the DPI.

People says that for a printable file, it should always be 300 DPI. So I set it up at 300 DPI.

What DPI would you suggest for filter effect?

I tried 100 DPI and the filter effect seemed to be different. (instead of being more pixelized)

Of course for printing 300 DPI is better. But for some kind of documents (like posters) 150 DPI can be enough.

However at the moment there is a problem with some filters which use Convolve Matrix : they must be imperatively rasterized at 90 DPI which is Inkscape default resolution because FeConvolveMatrix remains resolution dependent. This problem will be solved in the future but perhaps not in the near future. I tried to avoid the use of this primitive but it has so much possibilities that it wasn't possible. On the other hand it doesn't cause any problems for web graphics.

Another thing to check with Convolve Matrix : always avoid to place your object or image at a sub-pixel x or y location before exporting or creating a bitmap copy (I mean for example x = 124,000 pixels is much better than x = 124,001 pixels)

Thus before exporting to PDF, open the Filters Editor and check which filters you use contains a Convolve Matrix ; then create a 90 DPI bitmap copy of the objects which use these filters (nothing is necessary for the other filters ; they rasterize perfectly at 300 DPI) and export the whole page at 150 or 300 DPI. In most cases that will solve the problem.

ivan

I have made some test to a filter in particular with 2 different resolution. It seems that the pattern is less detailed in 150 DPI rather than 300 DPI. So the DPI does not only seem to be about resolution.

I have included the samples in this post.

One of the solution I found it to export the file as a 300DPI PNG and then print it in PDF. If I print from GIMP, the file will be much smaller because it automatically convert the file in JPG before printing it in PDF. Since it's in 300DPI, it doe snot make much differences.

To simplify the process, it would be interesting that the whole process could all be done within inkscape with the push of 1 button. The process is

Rasterise, Convert in JPG, then print in PDF.

larienna wrote:I have made some test to a filter in particular with 2 different resolution. It seems that the pattern is less detailed in 150 DPI rather than 300 DPI. So the DPI does not only seem to be about resolution.

I have included the samples in this post.

Thanks you for showing samples because you pointed a very special bug relative to the "Enamel jewelry" filter. If you try to export the same way for example "Cracked lava" filter or "Eroded metal" you will obtain exactly the same level of detail at any resolution, which obviously isn't the same here.

That's very important because exporting to PDF should give exactly what you see on screen in Inkscape even if you rasterize at 300 DPI while exporting to PDF !

I will fill a bug with your infos.

Thanks again,

ivan