Does the evaluateDe​tectionPre​cision function use the 11-point method to calculate mAP?

Hi,

Pretty much the title.

Thanks in advance.

Answer 1

[Pedro José Carrinho Ribeiro]

Ok, so I found the answer.

Apparently, Pascal VOC calculation changed over the years. It started as calculating mAP using 11 points for the precision-recall curve, and after some years, it changed to using all the unique points. So, if for the validation dataset, 120 points were originated for the precision-recall curve, those 120 points will also be used to calculate mAP, which corresponds to the AUC, in this case.

Short answer: No, it does not use the 11 point method. It uses the total number of unique points to calculate mAP.

Answer 2

[yanqi liu]

sir，its compute rule as follows

    precision = tp ./ (tp + fp);
    recall = tp ./ numExpected;

    % Change in recall for every true positive.
    deltaRecall = 1/numExpected; 

    ap = sum( precision .* (labels>0) ) * deltaRecall;

[Pedro José Carrinho Ribeiro]

Hi,

What does the numExpected represent? Is the ap calculated using all the point where the detector made inference?

Thanks in advance.

[yanqi liu]

sir, i think numExpected is the ideal or expect number return, offen use in recall