[magick-users] tiff convert slow

[Harm de Laat]

Hi all,

I have to resample some TIFF-G4 images to a lower resolution.

At this point the original images are rediculous large:

Image width: 45750 Image length: 31251
Resolution: 1270, 1270 pixels/inch

I need  to convert these images to a resolution of 300 DPI.

I use the following command:

convert -verbose -monitor wm_k.tif -resample 300x300 wm_k_300.tif

However, when I run this command on my Ubuntu box, it takes more than 24
hours to convert ONE image!

However, if I change the resolution to 72 DPI and use:

convert -verbose -monitor wm_k.tif -resample 72x72 wm_k_72.tif

the command completes in 19 minutes.

Why do both command take this enormous amount of time?
And how can I speed it up?

I need to convert more than 200 images per week, so I won't be able to wait
24 hours or more :)


Thank you very much,


Regards,

Harm de Laat
Kabisa ICT