Get list of grey algorithms

[lpatiny]

I would need to make a loop to test all the grey algorithms but it seems I have only the type definition:

image-js-typescript/src/operations/grey.ts

Lines 5 to 8 in c85e82d

	import * as greyAlgorithms from './greyAlgorithms';
	export type GreyAlgorithms = keyof typeof greyAlgorithms;

@targos May I expose greyAlgorithms property that would Object.keys(greyAlgorithms ?

[lpatiny]

In fact Threshold algorithms are an enum so we can loop through it.

export enum ThresholdAlgorithm {
  HUANG = 'HUANG',
  INTERMODES = 'INTERMODES',
  ISODATA = 'ISODATA',
  LI = 'LI',
  MAX_ENTROPY = 'MAX_ENTROPY',
  MEAN = 'MEAN',
  MIN_ERROR = 'MIN_ERROR',
  MINIMUM = 'MINIMUM',
  MOMENTS = 'MOMENTS',
  OTSU = 'OTSU',
  PERCENTILE = 'PERCENTILE',
  RENYI_ENTROPY = 'RENYI_ENTROPY',
  SHANBHAG = 'SHANBHAG',
  TRIANGLE = 'TRIANGLE',
  YEN = 'YEN',
}

Could we do the same for GreyAlgorithms ?

But in this case should we put everything in camelCase ? (grey algorithms are in camelCase and mask uppercase)

[stropitek]

We usually have the convention that variables names (or property names if in an object) for constants are uppercase. The value itself does not have to be uppercase but it simplifies everything if key and value are the same.

Also we prefer using const objects over enums:

export const ThresholdAlgorithm = {
  HUANG: 'HUANG',
  INTERMODES: 'INTERMODES',
} as const;

[targos]

Also we prefer using const objects over enums

#140