face-api/src/xception/TinyXception.ts

84 lines
3.0 KiB
TypeScript

import * as tf from '../../dist/tfjs.esm.js';
import { ConvParams, depthwiseSeparableConv } from '../common';
import { NetInput, TNetInput, toNetInput } from '../dom';
import { NeuralNetwork } from '../NeuralNetwork';
import { normalize } from '../ops';
import { range } from '../utils';
import { extractParams } from './extractParams';
import { extractParamsFromWeigthMap } from './extractParamsFromWeigthMap';
import { MainBlockParams, ReductionBlockParams, TinyXceptionParams } from './types';
function conv(x: tf.Tensor4D, params: ConvParams, stride: [number, number]): tf.Tensor4D {
return tf.add(tf.conv2d(x, params.filters, stride, 'same'), params.bias)
}
function reductionBlock(x: tf.Tensor4D, params: ReductionBlockParams, isActivateInput: boolean = true): tf.Tensor4D {
let out = isActivateInput ? tf.relu(x) : x
out = depthwiseSeparableConv(out, params.separable_conv0, [1, 1])
out = depthwiseSeparableConv(tf.relu(out), params.separable_conv1, [1, 1])
out = tf.maxPool(out, [3, 3], [2, 2], 'same')
out = tf.add(out, conv(x, params.expansion_conv, [2, 2]))
return out
}
function mainBlock(x: tf.Tensor4D, params: MainBlockParams): tf.Tensor4D {
let out = depthwiseSeparableConv(tf.relu(x), params.separable_conv0, [1, 1])
out = depthwiseSeparableConv(tf.relu(out), params.separable_conv1, [1, 1])
out = depthwiseSeparableConv(tf.relu(out), params.separable_conv2, [1, 1])
out = tf.add(out, x)
return out
}
export class TinyXception extends NeuralNetwork<TinyXceptionParams> {
private _numMainBlocks: number
constructor(numMainBlocks: number) {
super('TinyXception')
this._numMainBlocks = numMainBlocks
}
public forwardInput(input: NetInput): tf.Tensor4D {
const { params } = this
if (!params) {
throw new Error('TinyXception - load model before inference')
}
return tf.tidy(() => {
const batchTensor = tf.cast(input.toBatchTensor(112, true), 'float32');
const meanRgb = [122.782, 117.001, 104.298]
const normalized = normalize(batchTensor, meanRgb).div(tf.scalar(256)) as tf.Tensor4D
let out = tf.relu(conv(normalized, params.entry_flow.conv_in, [2, 2]))
out = reductionBlock(out, params.entry_flow.reduction_block_0, false)
out = reductionBlock(out, params.entry_flow.reduction_block_1)
range(this._numMainBlocks, 0, 1).forEach((idx) => {
out = mainBlock(out, params.middle_flow[`main_block_${idx}`])
})
out = reductionBlock(out, params.exit_flow.reduction_block)
out = tf.relu(depthwiseSeparableConv(out, params.exit_flow.separable_conv, [1, 1]))
return out
})
}
public async forward(input: TNetInput): Promise<tf.Tensor4D> {
return this.forwardInput(await toNetInput(input))
}
protected getDefaultModelName(): string {
return 'tiny_xception_model'
}
protected extractParamsFromWeigthMap(weightMap: tf.NamedTensorMap) {
return extractParamsFromWeigthMap(weightMap, this._numMainBlocks)
}
protected extractParams(weights: Float32Array) {
return extractParams(weights, this._numMainBlocks)
}
}