Fačko's profile - activity

I am using BOW to object categorization. My function looks like:

 def prepare_data_for_bow_sift(self, testing_paths, b_o_w):
        for p in self:
            image = cv2.imread(p, 0)
            kp, dsc = sift.detectAndCompute(image, None)
            if len(kp) < 1:
                # what to do now? how to handle if not keypoint found
            else:
                b_o_w.add(dsc)

Sometimes happens, that Surf or Sift do not find any keypoints. My question is, how to handle with this situation? What should I add to to bow traininig set? Is there any possibility to add any simple default empty descriptors? Or just delete the specific image from process of training?

Yeah thanks, I tried FaceRecognizer. EigenFaces works fine, but from Fisher and LBPH I get error as you can see : here

Here is example of my cropped image: link text

OK for better understanding. I did not skipped any detection. I have already trained cascade to detect ears and then I can easily crop the image. SO basically I am working now with image, which contains only ear. My point was, that if are there any possibility to compare Descriptors and get some vectors, which tell me how similar are picture. If I understood you correctly, there is no other options for classification only using machinelearning (SVM,KNN) right?

Yes that is right ,I am trying to predict which person it is.

ok my fault. So Is there any possibility to use these descriptors for classification?

I am working on ear Recognition project. I have database of ears, 60 person - each 4 ears. What I have already done, is that I detectAndCompute from each image Descriptors and Keypoints. Now I need to compare each image with each and find the best result.

What I did is that, I used BFMacther which returns matches link text . The larger the vector is, the difference between the images is smaller and are more similar right? So I saved the largest vector in comparison in one image with every other image and that is the result as the largest vector?

I am thinking now about second maybe better options?

I also found out, that is BFMatcher has method to train. So I can add every train Descriptors to BFMatcher and then call train. But now when I have trained BFMatcher how can I compare and get the result of my test vector?

Thank you.

This is my Python code:

import cv2 import numpy as np

img = cv2.imread('image.jpg') gray= cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)

star = cv2.xfeatures2d.StarDetector_create()

brief = cv2.BriefDescriptorExtractor_create()

kp = star.detect(gray,None)

kp,des=brief.compute(img,kp)

cv2.imshow('img',img) cv2.waitKey(0) cv2.destroyAllWindows()Blockquote

I am getting this error: File "earBRIEFsample.py", line 9, in <module> brief = cv2.BriefDescriptorExtractor_create() AttributeError: 'module' object has no attribute 'BriefDescriptorExtractor_create'

I also use SUFR, SIFT, ORB, FastFeature algorithms from library and didn' t have problem.

berak thanks you were right , it should look like std::vector<cv::rect> faces; face_cascade.detectMultiScale(mat, faces, 1.1, 2, 0, cv::Size(30, 30));

berak thanks you were right , it should look like std::vector<cv::rect> faces; face_cascade.detectMultiScale(mat, faces, 1.1, 2, 0, cv::Size(30, 30));

i can use only OpenCV version which supported Microsoft for Windows phone platform here

thanks, but this does not solve my problem

I work on CascadeClassifier MultiScale detection for WindowsPhone 8.1 C# using Windows Runtime Component. (Visual Studio 2013) Here is my code in WinRT:

cv::Mat mat(width, height, CV_8UC4);
cv::CascadeClassifier face_cascade;
face_cascade.load("haarcascade_frontalface_alt.xml");
std::vector<Rect> faces;
.
.
.
equalizeHist(mat, mat);
face_cascade.detectMultiScale(mat, faces, 1.1, 2, 0, Size(30, 30));

And I still get error: error C2664: 'void cv::CascadeClassifier::detectMultiScale(cv::InputArray,std::vector<_Ty> &,double,int,int,cv::Size,cv::Size)' : cannot convert parameter 2 from 'std::vector<_Ty>' to 'std::vector<_Ty> &'

I follow the tutorial on OpenCV website and I do not why my parameters should be wrong.

Thanks for reply.

Hello everybody,

I am beginner with OpenCV Windows Phone 8.1 programming , is there any useful tutorials?

Thanks for reply.