| face detection (via Python bridge) [message #93872] |
Mon, 14 November 2016 06:47  |
markb77
Messages: 217
Registered: July 2006
|
Senior Member |
|
|
hi,
I'm having some trouble using the IDL-Python bridge. I'm trying to run the face detection example from this blog post:
https://realpython.com/blog/python/face-recognition-with-pyt hon/
but my code is crashing at the point where it tries to detect the faces.
Here is the code:
pro test_python_face_detect
cv2 = Python.Import('cv2')
imagePath = 'C:\temp\FaceDetect\abba.png'
cascPath = 'C:\temp\FaceDetect\haarcascade_frontalface_default.xml'
; Create the haar cascade
faceCascade = cv2.CascadeClassifier(cascPath)
; Read the image
image = cv2.imread(imagePath)
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
; Detect faces in the image
faces = faceCascade.detectMultiScale(gray,scaleFactor=1.1, $
minNeighbors=5,minSize=[30,30], $
flags = cv2.cv.CV_HAAR_SCALE_IMAGE)
end
The error I'm getting is:
% PYTHON_CALLMETHOD: Exception: Required argument 'rejectLevels' (pos 2) not found.
The code works fine when run from Python.
I think it's likely that there are multiple things going wrong with my code. One of them is that IDL is not recognizing that I'm calling the detectMultiScale method using another calling convention (there are two different ways of calling detectMultiScale, for some reason). See the docs here:
http://docs.opencv.org/2.4/modules/objdetect/doc/cascade_cla ssification.html?highlight=detectmultiscale#cv2.CascadeClass ifier.detectMultiScale
Next, the IDL-Python bridge is not recognizing the keywords correctly, since the keywords are case sensitive.
What else? I don't know.
Does anyone have a suggestion on how to make this work? I would really like to be able to do face detection within IDL.
thanks
Mark
|
|
|
|
| Re: face detection (via Python bridge) [message #93874 is a reply to message #93872] |
Mon, 14 November 2016 08:31  |
Dick Jackson
Messages: 347
Registered: August 1998
|
Senior Member |
|
|
Hi Mark,
I've been working with some Python libraries, and when a colleague had a similar problem, she resorted to something like this (it's like using "Execute" in IDL… not optimal, perhaps, but it might do the job!):
Python.gray = gray
Python.scaleFactor = 1.1
Python.minNeighbors = 5
Python.minSize = [30,30]
Python.flags = cv2.cv.CV_HAAR_SCALE_IMAGE
void = Python.Run('faces = faceCascade.detectMultiScale(gray,scaleFactor=scaleFactor, minNeighbors=minNeighbors,minSize=minSize, flags=flags)')
faces = Python.faces
Does that work for you?
Cheers,
-Dick
Dick Jackson Software Consulting Inc.
Victoria, BC, Canada --- http://www.d-jackson.com
On Monday, 14 November 2016 06:47:13 UTC-8, superchromix wrote:
> hi,
>
> I'm having some trouble using the IDL-Python bridge. I'm trying to run the face detection example from this blog post:
>
> https://realpython.com/blog/python/face-recognition-with-pyt hon/
>
> but my code is crashing at the point where it tries to detect the faces.
>
> Here is the code:
>
> pro test_python_face_detect
>
> cv2 = Python.Import('cv2')
>
> imagePath = 'C:\temp\FaceDetect\abba.png'
> cascPath = 'C:\temp\FaceDetect\haarcascade_frontalface_default.xml'
>
> ; Create the haar cascade
> faceCascade = cv2.CascadeClassifier(cascPath)
>
> ; Read the image
> image = cv2.imread(imagePath)
> gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
>
> ; Detect faces in the image
>
> faces = faceCascade.detectMultiScale(gray,scaleFactor=1.1, $
> minNeighbors=5,minSize=[30,30], $
> flags = cv2.cv.CV_HAAR_SCALE_IMAGE)
>
>
> end
>
> The error I'm getting is:
>
> % PYTHON_CALLMETHOD: Exception: Required argument 'rejectLevels' (pos 2) not found.
>
> The code works fine when run from Python.
>
> I think it's likely that there are multiple things going wrong with my code. One of them is that IDL is not recognizing that I'm calling the detectMultiScale method using another calling convention (there are two different ways of calling detectMultiScale, for some reason). See the docs here:
>
> http://docs.opencv.org/2.4/modules/objdetect/doc/cascade_cla ssification.html?highlight=detectmultiscale#cv2.CascadeClass ifier.detectMultiScale
>
> Next, the IDL-Python bridge is not recognizing the keywords correctly, since the keywords are case sensitive.
>
> What else? I don't know.
>
> Does anyone have a suggestion on how to make this work? I would really like to be able to do face detection within IDL.
>
> thanks
> Mark
|
|
|
|
|
|
| Re: face detection (via Python bridge) [message #93878 is a reply to message #93875] |
Mon, 14 November 2016 15:45 |
Dick Jackson
Messages: 347
Registered: August 1998
|
Senior Member |
|
|
On Monday, 14 November 2016 11:21:14 UTC-8, superchromix wrote:
> Thanks for the suggestion, but it's not working yet. It this fails at the Python.Run statement, because the faceCascade object is not defined on the Python side. When I tried to add
>
> Python.faceCasecade = faceCascade
>
> it still didn't work.
>
> % PYTHON_RUN: Exception: name 'faceCascade' is not defined.
Sorry, Mark, I haven't actually installed the library and tried this, I'm tossing ideas off the top of my head…
Hmm, if that line is a direct quote, then it may be a typo (you have an extra "e" in the middle). That might fix it, or perhaps:
Python.gray = gray
Python.scaleFactor = 1.1
Python.minNeighbors = 5
Python.minSize = [30,30]
Python.flags = cv2.cv.CV_HAAR_SCALE_IMAGE
void = Python.Run('faces = cv2.CascadeClassifier.detectMultiScale(gray,scaleFactor=scal eFactor, minNeighbors=minNeighbors,minSize=minSize, flags=flags)')
faces = Python.faces
Of course, to try it more simply for now, how about:
Python.gray = gray
void = Python.Run('faces = cv2.CascadeClassifier.detectMultiScale(gray,scaleFactor=1.1, minNeighbors=5, minSize=[30,30], flags=cv2.cv.CV_HAAR_SCALE_IMAGE)')
faces = Python.faces
Is that any better?
Cheers,
-Dick
Dick Jackson Software Consulting Inc.
Victoria, BC, Canada --- http://www.d-jackson.com
|
|
|
|
|
|
comp.lang.idl-pvwave archive
Members
Search
Help
Login
Home
