Calculation of Accuracy for image retrieval

Total no of relevant images to be retrieved =20 TP= 8 FP=12 FN=12 TN=500 Acc=(8+500)/532=95% Likewise when TP=0,the accuracy will be, Acc=(0+494)/532=93% When TP=0,the classification accuracy is 93% whether this calculation is correct or should I use an another technique

Answer 1

[Image Analyst]

That could be fine, if it suits your needs. See the Wikipedia article on ROC Curves for more formulas: https://en.wikipedia.org/wiki/Receiver_operating_characteristic

[Nithya SIvasamy]

Thank you