do not create duplicates of the same objects
Submitted by Trevor Spiteri
Assigned to poppler-bugs
Description
Created attachment 128605 The pdf document used in the example output.
When I separate a pdf into pages and then unite it again, fonts are duplicated. The attached document a.pdf uses a regular font in page 1, and in page 2 it uses the same regular font as well as a bold font. After separating and uniting, the united file contains two copies of the regular font. It would be nice if the tools removed the identical duplicated fonts.
Details of an example are included below. Note that in the output to pdffonts, I removed the following columns which were common to all fonts:
type encoding emb sub uni
Type 1 Custom yes yes no
File sizes and font information:
$ wc -c a.pdf; pdffonts a.pdf 14244 a.pdf name object ID
ULOTVD+NimbusRomNo9L-Regu 4 0 EBGCWF+NimbusRomNo9L-Medi 10 0
$ pdfseparate a.pdf b%d.pdf
$ wc -c b1.pdf; pdffonts b1.pdf 8404 b1.pdf name object ID
ULOTVD+NimbusRomNo9L-Regu 4 0
$ wc -c b2.pdf; pdffonts b2.pdf 15120 b2.pdf name object ID
ULOTVD+NimbusRomNo9L-Regu 4 0 EBGCWF+NimbusRomNo9L-Medi 10 0
$ pdfunite b1.pdf b2.pdf c.pdf
$ wc -c c.pdf; pdffonts c.pdf 22916 c.pdf name object ID
ULOTVD+NimbusRomNo9L-Regu 4 0 ULOTVD+NimbusRomNo9L-Regu 23 0 EBGCWF+NimbusRomNo9L-Medi 29 0
$ pdfseparate c.pdf d%d.pdf
$ wc -c d1.pdf; pdffonts d1.pdf 8061 d1.pdf name object ID
ULOTVD+NimbusRomNo9L-Regu 4 0
$ wc -c d2.pdf; pdffonts d2.pdf 14778 d2.pdf name object ID
ULOTVD+NimbusRomNo9L-Regu 23 0 EBGCWF+NimbusRomNo9L-Medi 29 0
$ pdfunite d1.pdf d2.pdf e.pdf
$ wc -c e.pdf; pdffonts e.pdf 23296 e.pdf name object ID
ULOTVD+NimbusRomNo9L-Regu 4 0 ULOTVD+NimbusRomNo9L-Regu 42 0 EBGCWF+NimbusRomNo9L-Medi 48 0
Attachment 128605, "The pdf document used in the example output.":
a.pdf