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I am trying to use optical flow with opencv 2.4.5: calcOpticalFlowPyrLK()

I am using similar parameters to the demo of the opencv:

    Size winSize(6,6);     // Small window size
    calcOpticalFlowPyrLK(
        prevFrame, currentFrame, points[0], points[1], 
        status, err, winSize,
        0, termcrit, 0, 0.001             // Only the input image
    );

But as you can see I have set the maxLevels to 0 (so it will process only the current layer).

The problem is that this function sometimes returns a distance between points of over 100, if I do:

for(int i=0;i<points[1].size();i++) {
 if( !status[i] ) {                     
     continue;
  }

 cout << points[1][i] - points[0][i] << endl;

}

This sometime prints:

(53,120)

Meaning that y has a difference of over 120 pixels. Is that normal with a window size of only (6,6)? Note that this happens even if i give more layers in the pyramid.

I am trying to use optical flow with opencv 2.4.5: calcOpticalFlowPyrLK()

I am using similar parameters to the demo of the opencv:

    Size winSize(6,6);     // Small window size
    calcOpticalFlowPyrLK(
        prevFrame, currentFrame, points[0], points[1], 
        status, err, winSize,
        0, termcrit, 0, 0.001             // Only the input image
    );

But as you can see I have set the maxLevels to 0 (so it will process only the current layer).

The problem is that this function sometimes returns a distance between points of over 100, if I do:

for(int i=0;i<points[1].size();i++) {
 if( !status[i] ) {                     
     continue;
  }

 cout << points[1][i] - points[0][i] << endl;

}

This sometime prints:

(53,120)

Meaning that y has a difference of over 120 pixels. Is that normal with a window size of only (6,6)? Note that this happens even if i give more layers in the pyramid.

I am trying to use optical flow with opencv 2.4.5: calcOpticalFlowPyrLK()

I am using similar parameters to the demo of the opencv:

    Size winSize(6,6);     // Small window size
    calcOpticalFlowPyrLK(
        prevFrame, currentFrame, points[0], points[1], 
        status, err, winSize,
        0, termcrit, 0, 0.001             // Only the input image
    );

But as you can see I have set the maxLevels to 0 (so it will process only the current layer).

The problem is that this function sometimes returns a distance between points of over 100, if I do:

for(int i=0;i<points[1].size();i++) {
 if( !status[i] ) {                     
     continue;
  }

 cout << points[1][i] - points[0][i] << endl;

}

This sometime prints:

(53,120)

Meaning that y has a difference of over 120 pixels. Is that normal with a window size of only (6,6)? Note that this happens even if i give more layers in the pyramid.

Note that this happens especially when a point gets occluded or goes out of the scene

I am trying to use optical flow with opencv 2.4.5: calcOpticalFlowPyrLK()

I am using similar parameters to the demo of the opencv:

    Size winSize(6,6);     // Small window size
    calcOpticalFlowPyrLK(
        prevFrame, currentFrame, points[0], points[1], 
        status, err, winSize,
        0, termcrit, 0, 0.001             // Only the input image
    );

But as you can see I have set the maxLevels to 0 (so it will process only the current layer).

The problem is that this function sometimes returns a distance between points of over 100, if I do:

for(int i=0;i<points[1].size();i++) {
 if( !status[i] ) {                     
     continue;
  }

 cout << points[1][i] - points[0][i] << endl;

}

This sometime prints:

(53,120)

Meaning that y has a difference of over 120 pixels. Is that normal with a window size of only (6,6)? Note that this happens even if i give more layers in the pyramid.

Note that this happens especially when a point gets occluded or goes out of the scene

I am trying to use optical flow with opencv 2.4.5: calcOpticalFlowPyrLK()

I am using similar parameters to the demo of the opencv:

    Size winSize(6,6);     // Small window size
    calcOpticalFlowPyrLK(
        prevFrame, currentFrame, points[0], points[1], 
        status, err, winSize,
        0, termcrit, 0, 0.001             // Only the input image
    );

But as you can see I have set the maxLevels to 0 (so it will process only the current layer).

The problem is that this function sometimes returns a distance between points of over 100, if I do:

for(int i=0;i<points[1].size();i++) {
 if( !status[i] ) {                     
     continue;
  }

 cout << points[1][i] - points[0][i] << endl;

}

This sometime prints:

(53,120)

Meaning that y has a difference of over 120 pixels. Is that normal with a window size of only (6,6)? Note that this happens even if i give more layers in the pyramid.

Note that this happens especially when a point gets occluded or goes out of the scene