@tensorflow/tfjs-core
Version:
Hardware-accelerated JavaScript library for machine intelligence
70 lines • 3.4 kB
JavaScript
/**
* @license
* Copyright 2020 Google LLC. All Rights Reserved.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
* =============================================================================
*/
import { ENGINE } from '../engine';
import { MirrorPad } from '../kernel_names';
import { convertToTensor } from '../tensor_util_env';
import * as util from '../util';
import { op } from './operation';
/**
* Pads a `tf.Tensor` using mirror padding.
*
* This operation implements the `REFLECT` and `SYMMETRIC` modes of pad.
*
* ```js
* const x = tf.range(0, 9).reshape([1, 1, 3, 3]);
* x.mirrorPad([[0, 0], [0, 0], [2, 2], [2, 2]], 'reflect').print();
* ```
* @param x The tensor to pad.
* @param paddings An array of length `R` (the rank of the tensor), where
* each element is a length-2 tuple of ints `[padBefore, padAfter]`,
* specifying how much to pad along each dimension of the tensor.
* In "reflect" mode, the padded regions do not include the borders,
* while in "symmetric" mode the padded regions do include the borders.
* For example, if the input is `[1, 2, 3]` and paddings is `[0, 2]`,
* then the output is `[1, 2, 3, 2, 1]` in "reflect" mode, and
* `[1, 2, 3, 3, 2]` in "symmetric" mode.
* If `mode` is "reflect" then both `paddings[D, 0]` and `paddings[D, 1]`
* must be no greater than `x.shape[D] - 1`. If mode is "symmetric"
* then both `paddings[D, 0]` and `paddings[D, 1]` must be no greater than
* `x.shape[D]`
* @param mode String to specify padding mode. Can be `'reflect' | 'symmetric'`
*/
/** @doc {heading: 'Tensors', subheading: 'Transformations'} */
function mirrorPad_(x, paddings, mode) {
util.assert(mode === 'reflect' || mode === 'symmetric', () => `Invalid mode. Mode must be either reflect or symmetric. ` +
`Got ${mode}.`);
const $x = convertToTensor(x, 'x', 'mirrorPad');
if ($x.rank === 0) {
throw new Error('mirrorPad(scalar) is not defined. ' +
'Pass non-scalar to mirrorPad');
}
util.assert(paddings.length === $x.rank, () => `Padding doesn't match input. Must be ${$x.rank}. ` +
`Got ${paddings.length}.`);
const shapeOffset = mode === 'reflect' ? 1 : 0;
for (let i = 0; i < $x.rank; i++) {
util.assert(paddings[i].length === 2, () => `Invalid number of paddings. Must be length of 2 each.`);
util.assert(paddings[i][0] >= 0 && paddings[i][0] <= $x.shape[i] - shapeOffset &&
paddings[i][1] >= 0 && paddings[i][1] <= $x.shape[i] - shapeOffset, () => `Padding in dimension ${i} cannot be greater than or equal ` +
`to ${$x.shape[i] - shapeOffset} or less than 0 for input of ` +
`shape ${$x.shape}`);
}
const attrs = { paddings, mode };
const inputs = { x: $x };
return ENGINE.runKernel(MirrorPad, inputs, attrs);
}
export const mirrorPad = op({ mirrorPad_ });
//# sourceMappingURL=mirror_pad.js.map