import * as tf from '@tensorflow/tfjs-core'; function getCenterCoordinatesAndSizesLayer(x) { const vec = tf.unstack(tf.transpose(x, [1, 0])); const sizes = [ tf.sub(vec[2], vec[0]), tf.sub(vec[3], vec[1]) ]; const centers = [ tf.add(vec[0], tf.div(sizes[0], tf.scalar(2))), tf.add(vec[1], tf.div(sizes[1], tf.scalar(2))) ]; return { sizes, centers }; } function decodeBoxesLayer(x0, x1) { const { sizes, centers } = getCenterCoordinatesAndSizesLayer(x0); const vec = tf.unstack(tf.transpose(x1, [1, 0])); const div0_out = tf.div(tf.mul(tf.exp(tf.div(vec[2], tf.scalar(5))), sizes[0]), tf.scalar(2)); const add0_out = tf.add(tf.mul(tf.div(vec[0], tf.scalar(10)), sizes[0]), centers[0]); const div1_out = tf.div(tf.mul(tf.exp(tf.div(vec[3], tf.scalar(5))), sizes[1]), tf.scalar(2)); const add1_out = tf.add(tf.mul(tf.div(vec[1], tf.scalar(10)), sizes[1]), centers[1]); return tf.transpose(tf.stack([ tf.sub(add0_out, div0_out), tf.sub(add1_out, div1_out), tf.add(add0_out, div0_out), tf.add(add1_out, div1_out) ]), [1, 0]); } export function outputLayer(boxPredictions, classPredictions, params) { return tf.tidy(() => { const batchSize = boxPredictions.shape[0]; let boxes = decodeBoxesLayer(tf.reshape(tf.tile(params.extra_dim, [batchSize, 1, 1]), [-1, 4]), tf.reshape(boxPredictions, [-1, 4])); boxes = tf.reshape(boxes, [batchSize, (boxes.shape[0] / batchSize), 4]); const scoresAndClasses = tf.sigmoid(tf.slice(classPredictions, [0, 0, 1], [-1, -1, -1])); let scores = tf.slice(scoresAndClasses, [0, 0, 0], [-1, -1, 1]); scores = tf.reshape(scores, [batchSize, scores.shape[1]]); const boxesByBatch = tf.unstack(boxes); const scoresByBatch = tf.unstack(scores); return { boxes: boxesByBatch, scores: scoresByBatch }; }); } //# sourceMappingURL=outputLayer.js.map