OpenSlide Only Recognizing Topmost Layer

[jcupitt at gmail.com]

On 11 June 2014 09:57, Benjamin Gilbert <bgilbert at cs.cmu.edu> wrote:
> I noticed this in the im4java output:
>
>> Software: GraphicsMagick 1.3.19 2013-12-31 Q16 http://www.GraphicsMagick.org/
>
> im4java isn't using ImageMagick, it's using GraphicsMagick, which
> probably has a similar bug.  You could try reporting it to the
> GraphicsMagick developers.

This might not be a useful response, but you could also consider
another pyramid builder. VIPS (my project) is much faster than
GraphicsMagick and uses a lot less memory.

I tried on my laptop with quite a small image:

$ header summer8x3.tif
summer8x3.tif: 18008x22764 uchar, 3 bands, srgb, tiffload
$ time gm convert summer8x3.tif -define tiff:tile-geometry=256x256
-compress jpeg 'ptif:gm-pyr.tif'
real    0m50.992s
user    1m56.836s
sys    0m4.568s
peak mem: 2.4GB

My GraphicsMagick also seems to not set the sub-file type correctly.

$ time vips tiffsave summer8x3.tif vips-pyr.tif --tile --pyramid
--compression jpeg --tile-width 256 --tile-height 256
real    0m17.058s
user    0m17.348s
sys    0m1.072s
peak mem: 60MB

I tried with ImageMagick, but I think my laptop may not have enough
memory for this image

$ time convert summer8x3.tif -define tiff:tile-geometry=256x256
-compress jpeg 'ptif:im-pyr.tif'
real    7m20.224s
user    8m44.570s
sys    0m19.491s
peak mem: 4.7GB

It does set the sub-file type correctly though.

John