Re: CoreVideo to pixel level data (speed path problems)
Re: CoreVideo to pixel level data (speed path problems)
- Subject: Re: CoreVideo to pixel level data (speed path problems)
- From: "douglas a. welton" <email@hidden>
- Date: Mon, 16 Oct 2006 21:11:53 -0400
Jeremy,
(Hopefully I have read your post and understood it correctly...)
Check out the FrameReader object in the QCTV sample code. If I
remember correctly, if manipulates the the pixels from the CV buffer
directly into an image description... (No CIImage, No NSImage, No
bitmap reps)
Have you checked out the CIVideoDemoGL sample code? The -
exportMovie: routine in this sample uses the MovieExporter API and
grabs CV buffer data directly into an image description as well. If
you just want the Red pixels from a buffer, you should be able to
stick the CIColorCube filter into this code and get (something close
to) what you want.
Hope that helps.
later,
douglas
On Oct 16, 2006, at 8:03 PM, Jeremy Faller wrote:
I'm making a laser range finder: (http://www.pages.drexel.edu/
~twd25/webcam_laser_ranger.html)
I have written the SLANG filter for red filtering, and it works
fine. However, I think QuartzComposer SLANG filters fail for this
type of application.
On Oct 16, 2006, at 8:01 PM, John C. Randolph wrote:
I tend to do pixel-bashing with the help of Quartz Composer these
days. It's pretty easy to extract whatever pixel-level info you
want from a video stream using a QC "Core Image Kernel" patch with
a bit of GL SLANG code.
What are you trying to do with this red data?
-jcr
On Oct 16, 2006, at 4:39 PM, Jeremy Faller wrote:
All:
I am trying to take iSight data, and get the bitmap data for
post-processing. I am currently using the WhackedTV example from
Apple as a base, and it converts CVPixelBufferRef-->CIImage(s)--
>NSImage-->NSBitmapImageRep, but these operations are expensive
and slow. (I am seeing that converting the images to
NSBitmapImageRep can peg a processor at low frame rates. All of
the time is spent in [NSImage drawImage:], the final step to
convert NSImage(s) to NSBitmapImageRep.)
I am interested in knowing if there are any quick ways to
access the pixel level data in any of the data structures I am
using? Does anyone have any example code?
As a (possibly useful) aside, I am only interested in the red
data (from RGB) of the pixel data. If it helps, I would be glad
to sacrifice G/B/Alpha for just the red.
Thanks in advance.
John C. Randolph,
VP, Engineering
Stealth Imaging, Inc. <email@hidden>
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Cocoa-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
40earthlink.net
This email sent to email@hidden
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Cocoa-dev mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden