Iterate points for OpenCV's Line function

asked 2011-07-02 06:37:39 -0500

Kirielson
18 ●2 ●2 ●5

I'm trying to iterate from two tuples to create a line connection previous points to currents points.

    for (x,y) in currFeatures and (px,py) in self.prev_draw_features:
            cv.line(new_image, (px,py),(x,y),cv.RGB(125, 20,200),5)

Which then leads me to this error:

[ERROR] [WallTime: 1309631642.294530] bad callback: <bound method="" cached_subscriber.callback="" of="" <__main__.cached_subscriber="" instance="" at="" 0x2bbb290="">> Traceback (most recent call last): File "/opt/ros/diamondback/stacks/ros_comm/clients/rospy/src/rospy/topics.py", line 563, in _invoke_callback cb(msg) File "**", line 70, in callback for (x,y) in currFeatures and (px,py) in self.prev_draw_features: NameError: global name 'px' is not defined

Is it possible to iterate between two tuples at the exact same time, or will I need to construct a new variable to iterate between the elements. Keep in mind that the tuples may not be equal (which probably negates my "and" statement.

Thanks.

edit retag flag offensive close merge delete

add a comment

0

answered 2011-07-02 13:20:16 -0500

fergs

13902 ●59 ●157 ●196 http://www.robotandchisel.com

updated 2011-07-02 13:22:42 -0500

What you probably want is:

for ((x,y), (px,py)) in zip(currFeatures, self.prev_draw_features):
        cv.line(new_image, (px,py),(x,y),cv.RGB(125, 20,200),5)

edit flag offensive delete link

Comments

Okay I did try that but then I got the error: File "****", line 73, in callback cv.line(new_image, (px,py),(x,y),cv.RGB(125, 20,200),5) TypeError: <unknown> is not a numpy array Would I need to first extract all of the information out then re-insert it in?

Kirielson ( 2011-07-02 14:23:21 -0500 )edit

How do you get "new_image"? I think that is the only parameter that has to be a numpy array.

fergs ( 2011-07-03 04:56:16 -0500 )edit

I get new image from a live feed camera.

Kirielson ( 2011-07-05 01:46:57 -0500 )edit

Okay I got it fixed thanks!

Kirielson ( 2011-07-05 05:33:40 -0500 )edit

Could you post how you fixed it for the benefit of future users?

fergs ( 2011-07-05 08:20:55 -0500 )edit

Yeah I will.

Kirielson ( 2011-07-06 07:10:48 -0500 )edit

add a comment

0

answered 2011-07-06 07:15:31 -0500

Kirielson
18 ●2 ●2 ●5

I fixed it with two things,

First it's cv.Line not cv.line

Second of all, this is how you would want to do the listing:

for i in range(min(len (currFeatures), len (self.prev_draw_features))): # Find out which index is shorter
    currpoint = currFeatures[i]
    currpoint = (int(currpoint[0]), int(currpoint[1])) #Also code out the same setup for prev_draw_features
    cv.Line(new_image, currpoint, prevpoint, 123, 5)

edit flag offensive delete link

add a comment

Iterate points for OpenCV's Line function

2 Answers

Comments

Question Tools

Stats

Related questions

Iterate points for OpenCV's Line function edit

2 Answers

Comments

Question Tools

Stats

Related questions

Iterate points for OpenCV's Line function