I'd like to generate a full-page QR code from the command line. The following command sort of accomplishes this: qrencode -o- https://example.net | convert png:- -gravity center -units pixelsperinch -density 300 -resize 2551x3295 -extent 2551x3295 qrcode.pdf Unfortunately, the resulting QR code is quite blurry, as though imagemagick is doing some sort of unwanted antialiasing. Is there a way to make the code completely crisp, or just a better/simpler approach to generating a PDF file with a full-page QR code?

I have a PDF consisting of scanned pages with OCR done by tesseract. I want to downscale the images (by around 4x) and retain the OCR. What would be an automatic way to relink the OCR data to the new coordinates on the pages? --- Original question (*Sudden surge in the size of PDF generated by Ghostscript 9.55.0*): I have a large PDF and am unsuccessfully trying to reduce its size. (The file is copyrighted material, so I cannot post it; I am doing this for personal use. It must be a common problem, though: I had the same experience earlier with other files from different sources.) The file is a scan of a book with 1500 B&W A4 pages of text, no pictures at all. The individual pages were mogrify-ed into PNG images of equal height (around 1000px) and cleaned up via scantailor-advanced. Then each of the pages (now in TIFF) was tesseracted. The results were pdfunited into a 200MB file. This is way too large for this kind of book. I would like to be able to shrink it to around 30MB, perhaps 50. (The total text size extracted by pdftext is 9MB.) Most of the PDF compression methods I found on StackExchange and other sites boil down to gs with varying parameters. On my machine they all behave in a very similar way. I start gs in the terminal and switch to a GUI file manager. The size of the output file grows slowly and steadily from 0 to around 15MB (no matter the settings), and then it gallops in the last split second, as if gs gives up and just dumps the input into the output verbatim. (I attributed this to memory shortage, but the program also exhibits similar behavior on a relatively small, 100-page, part of this file.) If gs is not told to change the DPI (300), the output file becomes as large as the input was. If the DPI is changed to 72, the file becomes 70MB; this is still too much for such a loss in image quality. Is there an explanation of this surge? Should I perhaps use some other toolchain on the raw scans, or a different optimization tool? pdfsizeopt is very slow and seems to lead to 10% reduction. tiff2pdf -j 50 saves 5% (which will be re-added during OCR).

In GIMP, I can import a PDF, and use the GUI to flatten it (if it was made with many layers) by selecting Flatten Image in the Image dropdown menu. I can then export the PDF with a new filename. I would like to automate this. Is there some way to do it via the terminal?

I do have a pdf that contains a drawing, a part of which I would like to extract. I am able to open the pdf in inkscape. However, it contains a group with 150k items. As far as I see, there are no subgroups that I could select as entity. Now just trying to select the parts that I would like to delete does not work (inkscape still has 100% CPU load after 3 hours). Is there a command line tool that would allow me to crop the pdf *and* to delete the elements that are outside the cropped area? This would then allow me to further edit the extracted section using inkscape.

I asked here some months ago how to print and check results with lp command (CUPS) in Ubuntu. After few working around, I was able to print normal text files. I was able to print selecting some options (double sided print, media size, paper tray input, etc.) I got the linux drivers here (PPD files): https://www.openprinting.org/download/PPD/ Now I have a little problem: When I send a .pdf file to the printer (Ricoh MP Aficio 1106 EX connected by TCP-IP), the print goes slow, getting +30 seconds to send the file to the printer. The .txt files print at the moment I send them. Do you have any idea how to solve it? I tryied change the socket of the machine to 9100 port, but that only generates errors. EDIT1: I tryied using LPR command, instead LP: lpr -sPrinterIP /absolute/path/to/file.pdf But works slowly too. EDIT2: I installed qz-tray, a kind of print server/API. When I try PDF demo, it prints slow too. EDIT3: I tryied now with default PDF viewer (EVINCE) because I though I have a lack of memory and printed the same file. It worked well, at normal speed. EDIT4: I tyied some other drivers (generic and recomended by the printer maker ones), same speed. EDIT5: I found this link: https://en.opensuse.org/SDB:Using_Your_Own_Filters_to_Print_with_CUPS But cannot understand if filtering is "f..king me off", because my printer is a PCL one (and i am using a pxl driver...). Could anyone explain me this? EDIT 6: Found the origin of the problem: When I print a text-only-pdf file, it works like a charm. But when I send an image-pdf file, the print enters in a pre-print process (I cannot completely assure this) and get +30seconds to send any package to printer (this checked with wireshark). I can asume that PPD file (driver file provided by Ricoh Support) has anything in the code that send any order to process the file. I found this in the PPD file. I think is the root of this slowing problem: *%========== Ghostscript Command line ========== *FoomaticRIPCommandLine: "(printf '\033%%-12345X@PJL\n@PJL JOB\n@PJL SET COPIES=&copies;\n'%G|perl -p -e "s/\x26copies\x3b/1/" (gs -q -dBATCH -dPARANOIDSAFER -dNOPAUSE -dNOMEDIAATTRS -dNOINTERPOLATE %B%A%C %D%E | perl -p -e "s/^\x1b\x25-12345X//" | perl -p -e "s/\xc1\x01\x00\xf8\x31\x44/\x44/g" (printf '@PJL\n@PJL EOJ\n\033%%-12345X&apos" *End Found this article https://lists.linuxfoundation.org/pipermail/printing-foomatic/2012/002791.html taht confirms my ideas: the ppd driver is rendering all files with ghostcript. EDIT 7: Ricoh support told me that "lp" printing command may be using "default PDF viewer" to process the file, and slow the print process. I don't know how to check it. Thanks a lot.

I have pdf slides in landscape mode and would like to create a new pdf file containing the slides 4-up (in landscape mode again) like this: ----------------- | 1 | 2 | ----------------- | 3 | 4 | ----------------- I know that there is pdfjam (which can be used like this pdfjam --fitpaper true --nup 2x2 --delta '1mm 1mm' --scale 0.98 infile.pdf), but it does not preserve hyperlinks -- gs does, though. I am wondering how one could use gs to achieve the task (?) Alternatively, I mainly use 4-up to print slides. I couldn't manage to use lpr for achieving this. If someone has an idea for that, this would be interesting as well.

### System Info

alinuxchap@libertus-desktop:/usr/share/X11/xkb $ uname -a
Linux libertus-desktop 6.12.25+rpt-rpi-v8 #1 SMP PREEMPT Debian 1:6.12.25-1+rpt1 (2025-04-30) aarch64 GNU/Linux
alinuxchap@libertus-desktop:/usr/share/X11/xkb $

### Cmd

cd /home/alinuxchap/Documents/shared/dat/EDS/it
echo "" > output.txt
while read author; do
	echo $author
	pdfgrep "$author" *.pdf |& tee -a output.txt
done 

### Problem - grep outputs text matches in bold and red - I don't want to use grep -p as I also need to see the 'snippet' of context the term is being used in It's useful for archiving command output as 'logs'; the same problem arises with copy and paste, as that doesn't preserve rtf either.