Threshold For confidence score

Hi Guys

I would like if possible how to make this Threshold for Evaluation and validation of created R-CNN object Detector, i tried to make it in the attached scripts but it does not work, I want to make Threshold for score that like below 0.58 that score and bboxes should not be appeared in results

i tried the below code but i got the error

Herein the code:-

load('gTruth.mat')
smokedetection = selectLabels(gTruth,'alarm');
if ~isfolder(fullfile('EvaluationData'))
    
    mkdir EvaluationData
    addpath('EvaluationData');
    
    evaluationData = objectDetectorTrainingData(gTruth,...
    'SamplingFactor',1,'WriteLocation','EvaluationData');
end
imds = imageDatastore(fullfile('EvaluationData'));
numImages = height(evaluationData);
result(numImages,:) = struct('Boxes',[],'Scores',[]);
for i = 1:numImages
    
    % Read Image
    I = readimage(imds,i); 
    
    % Detect the object of interest
    [bboxes, scores] = detect(detector,I,'MiniBatchSize', 32);
    
    % Store result 
    result(i).Boxes = bboxes;
    T = 0.58; % Define threshold here
idx = scores >= T;
    result(i).Scores = scores(idx);
   
end
% Convert structure to table
results = struct2table(result);
overlap = 0.1;
% Evaluate Metrics
[ap,recall,precision] = evaluateDetectionPrecision(results...
    ,evaluationData(:,2),overlap);
[am,fppi,missRate] = evaluateDetectionMissRate(results,evaluationData(:,2),overlap);

% and herein the error i got
Error using vision.internal.detector.evaluationInputValidation>checkDetectionResultsTable (line 66)
Invalid score value in row 1 of the detection results table: Expected input to be an array with number of
elements equal to 8.

Error in vision.internal.detector.evaluationInputValidation (line 6)
    checkDetectionResultsTable(detectionResults, groundTruth, mfilename);

Error in evaluateDetectionPrecision (line 94)
vision.internal.detector.evaluationInputValidation(detectionResults, ...

Error in Evaluationthedetector (line 33)
[ap,recall,precision] = evaluateDetectionPrecision(results...
 
% Looking for your assistance
 

Answer 1

[Harsha Priya Daggubati]

Hi,

I suspect the issue is due to the threshold you are using, try storing the bounding boxes in results based on the threshold.

T = 0.58; % Define threshold here
idx = scores >= T;
result(i).Boxes = bboxes(idx);
result(i).Scores = scores(idx);

Hope this helps!