i posted this question on the "machine vision" forum, but did not get any answer. so i will try here...
i am using nivision 8, compiling with labwindows/cvi
i
need to transmit an image accross the network. the image has some
important informations overlaid onto it, which i absolutely need to
keep. however, the ni vision image structure is not self contained: instead of
being a single block of memory whose size can be computed, it is a set
of pointers to memory blocks scattered all over the memory. also, the
image structure is not documented (especially the way overlay
informations are stored), so i can't serialize it myself. how can i
transmit my image without losing any information ?
please note that:
-
merging the overlay is not an option: i will have to resize the image
on the destination computer. resizing before merging makes all overlay
object disappear, and resizing after merging results in an ugly image
where half the overlay has been cut-off by resampling.
- for
performance reason, i would like to avoid using a temporary file. i
don't know if imaqWriteVisionFile saves overlay informations (the
documentation is not clear on what is considered vision informations),
but writing to a file, transmitting it accross the network, saving it
to a file on the destination computer and opening it for display will
kill the throughput of the application.
(as a side
note: it would be nice if imaqWriteFile and the likes could write to an
already opened file. that would allow for example: to use a socket
handle instead of a file handle, or to embed the image into a file
along with external informations).
