trying to convert a series of canon raw .cr2 images with nconvert
i'm finding that i have this problem:
if my image (camera is a 5d, btw) is x x x i would normally
issue a command something like nconvert -crop 286 374 3856 2169
to get an image of a 16x9 ratio.
the image produced by the above is not correct, however. in order to get
my image to crop to the right size i have to divide all of the numbers
by 2. that produces a command:
nconvert -crop 143 187 1928 2169
this produces an image that is properly cropped.
i noticed similar behaviour with irfanview a while back and, among
other reasons, switches to xnview to solve the problem. i found
that irfanview misreported the image size in addition to being unable
to crop properly. i found that xnview did report the proper image size.
now that i'm getting in a little deeper, however, i'm finding this
similar problem with the cr2 files.
what's happening here? is xnview actually reading the file at half
it's dimensions? or is it just a bug wherein the numbers need to be
halved but the data is actually correct?
thanks and will continue testing,
BabaG
crop coordinates must be divided by 2
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although i've issued no -resize command, my cropped image
is the size it would have been if the original image was 1/4
the size it really is. iow, nconvert is performing as if my
cr2 image was actually 2193 x 1460 instead of 4386 x 2920.
to sum up, i have an image at 4386 x 2920. nconvert traets
it as though it were 2193 x 1460. if i determine my crop coordinates
on the full 4386 x 2920 image, i must divide the x/y and w/h
by 2 to get the proper image cropping output. that, however,
is still a problem because the cropped image, with only cropping,
no resizing, outputs as 1/4 the size of the expected output.
where i expect an output image of 3856 x 2169, i actually get
an output frame at 1928 x 1084.
is the size it would have been if the original image was 1/4
the size it really is. iow, nconvert is performing as if my
cr2 image was actually 2193 x 1460 instead of 4386 x 2920.
to sum up, i have an image at 4386 x 2920. nconvert traets
it as though it were 2193 x 1460. if i determine my crop coordinates
on the full 4386 x 2920 image, i must divide the x/y and w/h
by 2 to get the proper image cropping output. that, however,
is still a problem because the cropped image, with only cropping,
no resizing, outputs as 1/4 the size of the expected output.
where i expect an output image of 3856 x 2169, i actually get
an output frame at 1928 x 1084.
thankyou pierre! you might want to have a look at another post i made
yesterday which also has to do with cr2 files. it's in the general support
forum:
http://newsgroup.xnview.com/viewtopic.php?t=12402
in brief, i ran a script on a series of matched cr2 and jpg files. the
jpg's ran correctly but the cr2 files auto-compensated the exposure
even though nothing was done to command that behaviour. perhaps
these errors are tied together in some way?
thanks again and love the program!
BabaG
yesterday which also has to do with cr2 files. it's in the general support
forum:
http://newsgroup.xnview.com/viewtopic.php?t=12402
in brief, i ran a script on a series of matched cr2 and jpg files. the
jpg's ran correctly but the cr2 files auto-compensated the exposure
even though nothing was done to command that behaviour. perhaps
these errors are tied together in some way?
thanks again and love the program!
BabaG