Legacy ImageMagick Discussions Archive

ImageMagick 6.9.3-7 Q32 x86_64 2016-04-04

Apologies, my fault. I did put this in the message, but it was hidden somewhat

I used

..\convert t00.tif t01.tif t02.tif -evaluate-sequence mean t_mean.tif

and was expecting an integer result given the pixel values were integers

Hi

I used the following to calculate the mean pixel value from a series of 16bit input images (ImageMagick 6.9.1-2 Q16) as per

convert t00.tif t01.tif t02.tif -evaluate-sequence mean t_mean.tif

for the first pixel (for example) this gives values in the original images of 2312, 1276 and 4305, with ...

I tried this
convert t_mean.tif -precision 20 -format '%[pixel:p{40,30}]' info:-
srgb(3.464815393896963

which was OK, then this

convert t_mean.tif -precision 20 -format [fx:p{40,30}*r.32] info:-
convert: unable to open image `p30*r.32]': No such file or directory @ error/blob.c/OpenBlob/2702 ...

Version: ImageMagick 6.9.1-2 Q16 x86 2015-04-14

I using the following to extract a pixel value (I think this is a normalised percentage value)

convert t_mean.tif -precision 20 -format '%[pixel:p{40,30}]' info:-

Is there an easy way to get the actual pixel value itself?

thanks

mike

Hi

I have downloaded the latest IM sources and compiled under CentOS 7 using

make clean
./configure --enable-hdri
make
make install

After the configure command this is reported
CPPFLAGS -DMAGICKCORE_HDRI_ENABLE=1 -DMAGICKCORE_QUANTUM_DEPTH=16

The version is reported as

Version: ImageMagick 6 ...

Thanks very much - quick learning curve here! Q32 it is - Ill switch to Linux.

I dont have HDRI enabled (just read up on that) - how does this change processing?? I assume that by having a 32 bit TIF (under Q32) it becomes an RGB 96 bit image with calculations as floating point. What is different ...

Apologies for missing that. Version:
Version: ImageMagick 6.9.1-2 Q16 x86 2015-04-14

Will this have an impact?

For this application the 16 bit TIF has come from PTGui (which aligned the 3 images, but did *not* create an HDR). The identify command reports them as 16 bit - after conversion they are ...

Hi

I have three RGB 16 bit TIFFs which I converted to 32 bit as per (for each)

..\convert 02.tif -depth 32 test3202.tif

I then used evaluate-sequence to take the mean of each pixel over the set of three as per

..\convert *.tif -evaluate-sequence mean test.tif

I then did the same evaluation for ...