face-api.js
Version:
JavaScript API for face detection and face recognition in the browser with tensorflow.js
54 lines • 2.35 kB
JavaScript
export function nonMaxSuppression(boxes, scores, maxOutputSize, iouThreshold, scoreThreshold) {
var numBoxes = boxes.shape[0];
var outputSize = Math.min(maxOutputSize, numBoxes);
var candidates = scores
.map(function (score, boxIndex) { return ({ score: score, boxIndex: boxIndex }); })
.filter(function (c) { return c.score > scoreThreshold; })
.sort(function (c1, c2) { return c2.score - c1.score; });
var suppressFunc = function (x) { return x <= iouThreshold ? 1 : 0; };
var selected = [];
candidates.forEach(function (c) {
if (selected.length >= outputSize) {
return;
}
var originalScore = c.score;
for (var j = selected.length - 1; j >= 0; --j) {
var iou = IOU(boxes, c.boxIndex, selected[j]);
if (iou === 0.0) {
continue;
}
c.score *= suppressFunc(iou);
if (c.score <= scoreThreshold) {
break;
}
}
if (originalScore === c.score) {
selected.push(c.boxIndex);
}
});
return selected;
}
function IOU(boxes, i, j) {
var boxesData = boxes.arraySync();
var yminI = Math.min(boxesData[i][0], boxesData[i][2]);
var xminI = Math.min(boxesData[i][1], boxesData[i][3]);
var ymaxI = Math.max(boxesData[i][0], boxesData[i][2]);
var xmaxI = Math.max(boxesData[i][1], boxesData[i][3]);
var yminJ = Math.min(boxesData[j][0], boxesData[j][2]);
var xminJ = Math.min(boxesData[j][1], boxesData[j][3]);
var ymaxJ = Math.max(boxesData[j][0], boxesData[j][2]);
var xmaxJ = Math.max(boxesData[j][1], boxesData[j][3]);
var areaI = (ymaxI - yminI) * (xmaxI - xminI);
var areaJ = (ymaxJ - yminJ) * (xmaxJ - xminJ);
if (areaI <= 0 || areaJ <= 0) {
return 0.0;
}
var intersectionYmin = Math.max(yminI, yminJ);
var intersectionXmin = Math.max(xminI, xminJ);
var intersectionYmax = Math.min(ymaxI, ymaxJ);
var intersectionXmax = Math.min(xmaxI, xmaxJ);
var intersectionArea = Math.max(intersectionYmax - intersectionYmin, 0.0) *
Math.max(intersectionXmax - intersectionXmin, 0.0);
return intersectionArea / (areaI + areaJ - intersectionArea);
}
//# sourceMappingURL=nonMaxSuppression.js.map