CODEWITHSUNDEEP
imagemagickpng
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Reputation: 10919

ImageMagick create large blank image without using lots of disk

How can I create a large blank image with ImageMagick without using gigabytes of disk space? 

convert -debug All -size 100000x100000 canvas:white big_white.png

This takes at least 8 GB of disk space since it won't run with ImageMagick policy disk set to 8 GB.

Upvotes: 2

Views: 741

Answers (1)

Mark Setchell
Mark Setchell

Reputation: 207465

If your aim is to create a 100,000x100,000 blank PNG, I would recommend libvips to you. It is very frugal with resources compared to ImageMagick.

So, to create a 100000x100000 pixel black PNG in Terminal:

vips black black.png 100000 100000 --bands 3

takes 300s on my machine and uses 227MB of RAM. I tested with:

/usr/bin/time -l vips black black.png 100000 100000 --bands 3

If you insist on making that white, you can invert it:

vips invert black.png white.png

which takes 360s on my machine and uses 406MB of RAM.

By comparison, ImageMagick needs 3,300 seconds and ?? GB of RAM to do the same:

/usr/bin/time -l convert -size 100000x100000 canvas:white big_white.png

By the way, you should be more specific about whether you want a greyscale or a colour PNG, whether a palletised image is acceptable or not, and whether you want 8-bits/sample or 16-bits/sample.

Upvotes: 1

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