Bug 458789

Summary:	digikam gets slow trying to make thumbnails for 26k scanned color A4 pages (PNM format)
Product:	[Applications] digikam	Reporter:	hps <hps>
Component:	Database-Thumbs	Assignee:	Digikam Developers <digikam-bugs-null>
Status:	REPORTED ---
Severity:	wishlist	CC:	caulier.gilles
Priority:	NOR
Version:	7.7.0
Target Milestone:	---
Platform:	FreeBSD Ports
OS:	FreeBSD
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description hps@selasky.org 2022-09-06 14:56:44 UTC

SUMMARY

Can the thumbnail process be made less CPU intensive? And also thumbnail only what is in the current view?

STEPS TO REPRODUCE
1. Fill up a folder with 26k 300 DPI color A4 pnm pictures.
2. Add this folder to digikam

OBSERVED RESULT

3. Digikam becomes mostly unresponsive, trying to make thumbnails.

EXPECTED RESULT

"Digikam should not eat too much at a time." Maybe put a configurable sleep or CPU cap on the thumbnailing process.

SOFTWARE/OS VERSIONS
ALL

KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 5.x

ADDITIONAL INFORMATION

NONE

Comment 1 caulier.gilles 2022-09-06 15:15:51 UTC

Can you share by cloud some samples of PNM images to try to reproduce

Gilles Caulier

Comment 2 hps@selasky.org 2022-09-06 15:20:22 UTC

(In reply to caulier.gilles from comment #1)
> Can you share by cloud some samples of PNM images to try to reproduce
> 
> Gilles Caulier

Hi,

Any 27 megabyte .PNM will do:

27606699 bytes image.pnm

And then make thousands of them and add that folder to DigiKam. Yes, I know it's a lot of disk space.

Then especially if that folder is on a 1GBit/s network share, things starting to go slow as you can probably guess.

--HPS

Comment 3 hps@selasky.org 2022-09-06 15:23:18 UTC

(In reply to hps@selasky.org from comment #2)
> (In reply to caulier.gilles from comment #1)
> > Can you share by cloud some samples of PNM images to try to reproduce
> > 
> > Gilles Caulier
> 
> Hi,
> 
> Any 27 megabyte .PNM will do:
> 
> 27606699 bytes image.pnm
> 
> And then make thousands of them and add that folder to DigiKam. Yes, I know
> it's a lot of disk space.
> 
> Then especially if that folder is on a 1GBit/s network share, things
> starting to go slow as you can probably guess.
> 
> --HPS

image.pnm PPM 2598x3542 2598x3542+0+0 8-bit sRGB 26.3278MiB 0.094u 0:00.169