Image Writing Issue about pyvips HOT 4 CLOSED

Hello, you need to raise the maximum number of open files. I have mine set at 64000, for example.

john@yingna ~ $ ulimit -n
64000

Exactly how to raise the number will need a bit of searching. It seems to vary a lot between linuxes.

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Thanks @jcupitt

I tried to set it before but the maximum ulimit - n was 4096 and I failed to set it more. I followed this issue https://superuser.com/questions/1200539/cannot-increase-open-file-limit-past-4096-ubuntu and it worked well.
Can you suggest any other pipeline which I should implement to decrease RAM uses? Right now its taking 13.5GB for 80X80 images. I am first making each rows and then merging all the rows vertically.

Also when I save the stitched row images in drive and load it again using pyvips.Image.new_from_file(join(mydir,img)) to stitch it vertically, it takes less memory but takes more time, it's obvious. is there any other method to do it faster?

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You could build as sets of 2x2 blocks. So join the four in the top left as

A B 
C D

Then the next 2x2 block, and so on. Then do another pass and join up the 2x2 blocks in the same way, and repeat until the whole image is joined.

You can drop the concurrency down. Try VIPS_CONCURRENCY=1 before running your program.

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Thanks for the suggestion. Closing this issue.

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