Hi Bill,
What is the encoding of the images that you're viewing?
> rostopic echo [image_topic]/encoding
The following is based on image_view/src/image_view.cpp:
It looks like image view converts all incoming messages into a "bgr8"
encoding. Thus, if the incoming format is anything other than bgr8,
cv_bridge will convert every pixel to bgr8, possibly resulting in the high
CPU load:
if (img_bridge_.fromImage(*msg, "bgr8"))
cvShowImage(window_name_.c_str(), img_bridge_.toIpl());
else
ROS_ERROR("Unable to convert %s image to bgr8",
msg->encoding.c_str());
I'm guessing this could be optimized a bit.
Vijay
On Fri, Jun 18, 2010 at 9:32 AM, Kurt Konolige <
konolige@willowgarage.com>wrote:
> Bill, at least for image_proc, it depends on what you're doing and how
> fast your cpu is. If image_proc is converting from Bayer to color,
> and/or doing rectification, it can use some cpu, especially if you
> have a 1.4 GHz machine, not especially fast these days. image_view
> may be scaling the image, I'm not sure about this.
>
> My guess is that the overhead isn't in the message passing, but we
> need to test this.
>
> Cheers --Kurt
>
> On Fri, Jun 18, 2010 at 9:21 AM, Bill Morris <morris@ee.ccny.cuny.edu>
> wrote:
> > Is there any particular reason that image_proc and image_view use so
> > much cpu?
> >
> > CPU0: Intel(R) Core(TM)2 Duo CPU T5270 @ 1.40GHz stepping 0d
> >
> > PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+
> > COMMAND
> > 12247 user 20 0 101m 18m 12m S 15 0.9 0:09.97
> > image_view
> > 12249 user 20 0 101m 18m 12m S 15 0.9 0:09.10
> > image_view
> > 12248 user 20 0 99.1m 15m 9740 S 15 0.8 0:11.15
> > image_proc
> > 12246 user 20 0 95528 26m 10m S 13 1.3 0:08.27
> > usb_cam_node
> >
> > Is this mostly messaging overhead that could be fixed by moving to
> > nodelets? Has there been much work been done to optimize the nodes
> > within the image_pipeline package?
> >
> >
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> >
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