/
threshold.ts
62 lines (53 loc) · 1.75 KB
/
threshold.ts
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/*
* Copyright (c) 2016-present Invertase Limited
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this library 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 * as superstruct from 'superstruct';
import * as utils from '../utils';
import { OperationBuilder } from '../types';
/**
* The user visible name of this operation.
*/
const name = 'threshold';
/**
* Any pixel value greater than or equal to the threshold value will be set to 255, otherwise it will be set to 0.
*/
const struct = superstruct.object({
operation: superstruct.literal(name),
/**
* A value in the range 0-255 representing the level at which the threshold will be applied. (optional, default 128)
*/
threshold: superstruct.defaulted(
utils.coerceStringToInt(superstruct.size(superstruct.integer(), 0, 255)),
128,
),
/**
* Convert to single channel grayscale. (optional, default true)
*/
grayscale: superstruct.optional(utils.coerceStringToBoolean()),
});
export type OperationThreshold = superstruct.Infer<typeof struct>;
export const operationThreshold: OperationBuilder = {
name,
struct,
build(operation) {
const options = operation.options as OperationThreshold;
return [
{
method: name,
arguments: [options.threshold, utils.omitKey(options, 'grayscale')],
},
];
},
};