After some fiddling with imagemagick I have found that if I call :
convert -monitor image1.jpg miff:- | convert - -monitor -auto-level test-image.jpg
I get this in the display in the miff:- :
------------------------------------------
Save/Image/C:/DOCUME~1/s0976/LOCALS~1/Temp[magick-Itb0w5PE]: 2101 of 2112, 99% complete
....
( lots of text lines)
Save/Image/C:/DOCUME~1/s0976/LOCALS~1/Temp[magick-Itb0w5PE]: 2111 of 2112, 100% complete
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It seems that the "miff:-" option + "monitor" has an extra "CR LF" at the end of the display ...
Any ideas to solve this ?