test/png/decode/ancillary/histogram.js
// Copyright 2015 Yahoo! Inc.
// Copyrights licensed under the Mit License. See the accompanying LICENSE file for terms.
var testGen = require('../../testGen');
var expect = require('chai').expect;
describe('Histogram', function () {
describe('15 colors', function () {
testGen.addDecodeTests({
resourceGroup: ['ancillary', 'histogram'],
resourceFile: 'ch1n3p04',
imageCheck: true,
chunkTypes: ['gAMA', 'hIST', 'PLTE'],
headerCheck: true,
width: 32,
height: 32,
bitDepth: 4,
colorType: 3,
filter: 0,
compression: 0,
interlace: 0
});
it('should have volatile data', function () {
expect(this.data.volatile).to.be.not.undefined;
});
it('should have a histogram', function () {
expect(this.data.volatile.histogram).to.be.not.undefined;
});
it('should have a length of 15 histogram values', function () {
expect(this.data.volatile.histogram).to.be.an('array');
expect(this.data.volatile.histogram.length).to.be.equal(15);
});
it('should have histogram values', function () {
expect(this.data.volatile.histogram).to.be.deep.equal([
64, 112, 48, 96, 96, 32, 32, 80, 16, 128, 64, 16, 48, 80, 112
]);
});
it('should have the same length as the PLTE chunk', function () {
expect(this.data.volatile.histogram.length).to.be.equal(this.data.volatile.paletteColors.length);
});
});
describe('256 colors', function () {
testGen.addDecodeTests({
resourceGroup: ['ancillary', 'histogram'],
resourceFile: 'ch2n3p08',
imageCheck: true,
chunkTypes: ['gAMA', 'hIST', 'PLTE'],
headerCheck: true,
width: 32,
height: 32,
bitDepth: 8,
colorType: 3,
filter: 0,
compression: 0,
interlace: 0
});
it('should have volatile data', function () {
expect(this.data.volatile).to.be.not.undefined;
});
it('should have a histogram', function () {
expect(this.data.volatile.histogram).to.be.not.undefined;
});
it('should have a length of 256 histogram values', function () {
expect(this.data.volatile.histogram).to.be.an('array');
expect(this.data.volatile.histogram.length).to.be.equal(256);
});
it('should have the same length as the PLTE chunk', function () {
expect(this.data.volatile.histogram.length).to.be.equal(this.data.volatile.paletteColors.length);
});
});
});