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1/**
2 * @license
3 * Copyright 2020 Google LLC. All Rights Reserved.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 * =============================================================================
16 */
17import { ENGINE } from '../engine';
18import { MaxPool } from '../kernel_names';
19import { convertToTensor } from '../tensor_util_env';
20import * as util from '../util';
21import * as conv_util from './conv_util';
22import { op } from './operation';
23import { reshape } from './reshape';
24/**
25 * Computes the 2D max pooling of an image.
26 *
27 * @param x The input tensor, of rank 4 or rank 3 of shape
28 * `[batch, height, width, inChannels]`. If rank 3, batch of 1 is assumed.
29 * @param filterSize The filter size: `[filterHeight, filterWidth]`. If
30 * `filterSize` is a single number, then `filterHeight == filterWidth`.
31 * @param strides The strides of the pooling: `[strideHeight, strideWidth]`. If
32 * `strides` is a single number, then `strideHeight == strideWidth`.
33 * @param dilations The dilation rates: `[dilationHeight, dilationWidth]`
34 * in which we sample input values across the height and width dimensions
35 * in dilated pooling. Defaults to `[1, 1]`. If `dilations` is a single
36 * number, then `dilationHeight == dilationWidth`. If it is greater than
37 * 1, then all values of `strides` must be 1.
38 * @param pad The type of padding algorithm.
39 * - `same` and stride 1: output will be of same size as input,
40 * regardless of filter size.
41 * - `valid`: output will be smaller than input if filter is larger
42 * than 1x1.
43 * - For more info, see this guide:
44 * [https://www.tensorflow.org/api_guides/python/nn#Convolution](
45 * https://www.tensorflow.org/api_guides/python/nn#Convolution)
46 * @param dimRoundingMode A string from: 'ceil', 'round', 'floor'. If none is
47 * provided, it will default to truncate.
48 */
49function maxPool_(x, filterSize, strides, pad, dimRoundingMode) {
50 const $x = convertToTensor(x, 'x', 'maxPool');
51 const dilations = 1;
52 let x4D = $x;
53 let reshapedTo4D = false;
54 if ($x.rank === 3) {
55 reshapedTo4D = true;
56 x4D = reshape($x, [1, $x.shape[0], $x.shape[1], $x.shape[2]]);
57 }
58 util.assert(x4D.rank === 4, () => `Error in maxPool: input must be rank 4 but got rank ${x4D.rank}.`);
59 util.assert(conv_util.eitherStridesOrDilationsAreOne(strides, dilations), () => 'Error in maxPool: Either strides or dilations must be 1. ' +
60 `Got strides ${strides} and dilations '${dilations}'`);
61 if (dimRoundingMode != null) {
62 util.assert(util.isInt(pad), () => `Error in maxPool: pad must be an integer when using, ` +
63 `dimRoundingMode ${dimRoundingMode} but got pad ${pad}.`);
64 }
65 const inputs = { x: x4D };
66 const attrs = { filterSize, strides, pad, dimRoundingMode };
67 // tslint:disable-next-line: no-unnecessary-type-assertion
68 const res = ENGINE.runKernel(MaxPool, inputs, attrs);
69 if (reshapedTo4D) {
70 return reshape(res, [res.shape[1], res.shape[2], res.shape[3]]);
71 }
72 return res;
73}
74export const maxPool = op({ maxPool_ });
75//# sourceMappingURL=max_pool.js.map
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