pdfkit/tests/unit/png.spec.js

import PDFDocument from '../../lib/document';
import PDFReference from '../../lib/reference';
import PNGImage from '../../lib/image/png';
import fs from 'fs';

describe('PNGImage', () => {
  let document;

  const createImage = fileName => {
    const img = new PNGImage(fs.readFileSync(fileName), 'I1');
    // noop data manipulation methods
    img.loadIndexedAlphaChannel = () => {
      if (img.image.transparency.indexed) {
        img.alphaChannel = {};
        img.finalize();
      }
    };
    img.splitAlphaChannel = () => {
      if (img.image.hasAlphaChannel) {
        img.alphaChannel = {};
        img.finalize();
      }
    };
    img.decodeData = () => {
      img.finalize();
    };
    const finalizeFn = img.finalize;
    jest.spyOn(img, 'finalize').mockImplementation(() => finalizeFn.call(img));
    img.embed(document);
    return img;
  };

  beforeEach(() => {
    document = new PDFDocument();
  });

  test('RGB', () => {
    // ImageWidth = 400
    // ImageHeight = 533
    // BitDepth = 8
    // ColorType = 2 (RGB)
    // Compression = 0
    // Filter = 0
    // Interlace = 0

    const img = createImage('./examples/images/test2.png');

    expect(img.finalize).toBeCalledTimes(1);

    expect(img.obj.data).toMatchObject({
      BitsPerComponent: 8,
      ColorSpace: 'DeviceRGB',
      Filter: 'FlateDecode',
      Height: 533,
      Length: 397011,
      Subtype: 'Image',
      Type: 'XObject',
      Width: 400,
      DecodeParms: expect.any(PDFReference)
    });

    expect(img.obj.data.DecodeParms.data).toMatchObject({
      BitsPerComponent: 8,
      Colors: 3,
      Columns: 400,
      Predictor: 15
    });
  });

  test('RGB white transparent', () => {
    // ImageWidth = 32
    // ImageHeight = 32
    // BitDepth = 16
    // ColorType = 2
    // Compression = 0
    // Filter = 0
    // Interlace = 0

    const img = createImage(
      './tests/images/pngsuite-rgb-transparent-white.png'
    );

    expect(img.finalize).toBeCalledTimes(1);

    expect(img.obj.data).toMatchObject({
      BitsPerComponent: 16,
      ColorSpace: 'DeviceRGB',
      Filter: 'FlateDecode',
      Height: 32,
      Length: 1932,
      Subtype: 'Image',
      Type: 'XObject',
      Width: 32,
      Mask: [255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255],
      DecodeParms: expect.any(PDFReference)
    });

    expect(img.obj.data.DecodeParms.data).toMatchObject({
      BitsPerComponent: 16,
      Colors: 3,
      Columns: 32,
      Predictor: 15
    });
  });

  test('RGB (8bit) with Alpha', () => {
    // ImageWidth = 409
    // ImageHeight = 400
    // BitDepth = 8
    // ColorType = 6 (RGB with Alpha)
    // Compression = 0
    // Filter = 0
    // Interlace = 0

    const img = createImage('./tests/images/bee.png');

    expect(img.finalize).toBeCalledTimes(1);

    expect(img.obj.data).toMatchObject({
      BitsPerComponent: 8,
      ColorSpace: 'DeviceRGB',
      Filter: 'FlateDecode',
      Height: 400,
      Length: 47715,
      Subtype: 'Image',
      Type: 'XObject',
      Width: 409,
      SMask: expect.any(PDFReference)
    });

    expect(img.obj.data.SMask.data).toMatchObject({
      BitsPerComponent: 8,
      ColorSpace: 'DeviceGray',
      Decode: [0, 1],
      Filter: 'FlateDecode',
      Height: 400,
      Length: 16,
      Subtype: 'Image',
      Type: 'XObject',
      Width: 409
    });
  });

  test('RGB (16bit) with Alpha', () => {
    // ImageWidth = 175
    // ImageHeight = 65
    // BitDepth = 16
    // ColorType = 6
    // Compression = 0
    // Filter = 0
    // Interlace = 0

    const img = createImage('./tests/images/straight.png');

    expect(img.finalize).toBeCalledTimes(1);

    expect(img.obj.data).toMatchObject({
      BitsPerComponent: 8,
      ColorSpace: 'DeviceRGB',
      Filter: 'FlateDecode',
      Height: 65,
      Length: 28537,
      Subtype: 'Image',
      Type: 'XObject',
      Width: 175,
      SMask: expect.any(PDFReference)
    });

    expect(img.obj.data.SMask.data).toMatchObject({
      BitsPerComponent: 8,
      ColorSpace: 'DeviceGray',
      Decode: [0, 1],
      Filter: 'FlateDecode',
      Height: 65,
      Length: 16,
      Subtype: 'Image',
      Type: 'XObject',
      Width: 175
    });
  });

  test('Pallete', () => {
    // ImageWidth = 980
    // ImageHeight = 540
    // BitDepth = 8
    // ColorType = 3 (Pallete)
    // Compression = 0
    // Filter = 0
    // Interlace = 0

    const img = createImage('./examples/images/test3.png');

    expect(img.finalize).toBeCalledTimes(1);

    expect(img.obj.data).toMatchObject({
      BitsPerComponent: 8,
      ColorSpace: ['Indexed', 'DeviceRGB', 255, expect.any(PDFReference)],
      Filter: 'FlateDecode',
      Height: 540,
      Length: 56682,
      Subtype: 'Image',
      Type: 'XObject',
      Width: 980,
      DecodeParms: expect.any(PDFReference)
    });

    expect(img.obj.data.DecodeParms.data).toMatchObject({
      BitsPerComponent: 8,
      Colors: 1,
      Columns: 980,
      Predictor: 15
    });
  });

  test('Pallete indexed transparency', () => {
    // ImageWidth = 32
    // ImageHeight = 32
    // BitDepth = 8
    // ColorType = 3
    // Compression = 0
    // Filter = 0
    // Interlace = 0

    const img = createImage(
      './tests/images/pngsuite-palette-transparent-white.png'
    );

    expect(img.finalize).toBeCalledTimes(1);

    expect(img.obj.data).toMatchObject({
      BitsPerComponent: 8,
      ColorSpace: ['Indexed', 'DeviceRGB', 244, expect.any(PDFReference)],
      Filter: 'FlateDecode',
      Height: 32,
      Length: 650,
      Subtype: 'Image',
      Type: 'XObject',
      Width: 32,
      DecodeParms: expect.any(PDFReference),
      SMask: expect.any(PDFReference)
    });

    expect(img.obj.data.DecodeParms.data).toMatchObject({
      BitsPerComponent: 8,
      Colors: 1,
      Columns: 32,
      Predictor: 15
    });

    expect(img.obj.data.SMask.data).toMatchObject({
      BitsPerComponent: 8,
      ColorSpace: 'DeviceGray',
      Decode: [0, 1],
      Filter: 'FlateDecode',
      Height: 32,
      Length: 16,
      Subtype: 'Image',
      Type: 'XObject',
      Width: 32
    });
  });

  test('Grayscale', () => {
    // ImageWidth = 428
    // ImageHeight = 320
    // BitDepth = 8
    // ColorType = 0
    // Compression = 0
    // Filter = 0
    // Interlace = 0

    const img = createImage('./tests/images/glassware-noisy.png');

    expect(img.finalize).toBeCalledTimes(1);

    expect(img.obj.data).toMatchObject({
      BitsPerComponent: 8,
      ColorSpace: 'DeviceGray',
      Filter: 'FlateDecode',
      Height: 428,
      Length: 82633,
      Subtype: 'Image',
      Type: 'XObject',
      Width: 320,
      DecodeParms: expect.any(PDFReference)
    });
  });

  test('Grayscale black transparent', () => {
    // ImageWidth = 32
    // ImageHeight = 32
    // BitDepth = 4
    // ColorType = 0
    // Compression = 0
    // Filter = 0
    // Interlace = 0

    const img = createImage(
      './tests/images/pngsuite-gray-transparent-black.png'
    );

    expect(img.finalize).toBeCalledTimes(1);

    expect(img.obj.data).toMatchObject({
      BitsPerComponent: 4,
      ColorSpace: 'DeviceGray',
      Filter: 'FlateDecode',
      Height: 32,
      Length: 328,
      Subtype: 'Image',
      Type: 'XObject',
      Width: 32,
      Mask: [0, 0],
      DecodeParms: expect.any(PDFReference)
    });

    expect(img.obj.data.DecodeParms.data).toMatchObject({
      BitsPerComponent: 4,
      Colors: 1,
      Columns: 32,
      Predictor: 15
    });
  });

  test('Grayscale white transparent', () => {
    // ImageWidth = 32
    // ImageHeight = 32
    // BitDepth = 16
    // ColorType = 0
    // Compression = 0
    // Filter = 0
    // Interlace = 0

    const img = createImage(
      './tests/images/pngsuite-gray-transparent-white.png'
    );

    expect(img.finalize).toBeCalledTimes(1);

    expect(img.obj.data).toMatchObject({
      BitsPerComponent: 16,
      ColorSpace: 'DeviceGray',
      Filter: 'FlateDecode',
      Height: 32,
      Length: 1212,
      Subtype: 'Image',
      Type: 'XObject',
      Width: 32,
      Mask: [255, 255],
      DecodeParms: expect.any(PDFReference)
    });

    expect(img.obj.data.DecodeParms.data).toMatchObject({
      BitsPerComponent: 16,
      Colors: 1,
      Columns: 32,
      Predictor: 15
    });
  });

  test('Grayscale with Alpha', () => {
    // ImageWidth = 112
    // ImageHeight = 112
    // BitDepth = 8
    // ColorType = 4 (Grayscale with Alpha)
    // Compression = 0
    // Filter = 0
    // Interlace = 0

    const img = createImage('./tests/images/fish.png');

    expect(img.finalize).toBeCalledTimes(1);

    expect(img.obj.data).toMatchObject({
      BitsPerComponent: 8,
      ColorSpace: 'DeviceGray',
      Filter: 'FlateDecode',
      Height: 112,
      Length: 9922,
      Subtype: 'Image',
      Type: 'XObject',
      Width: 112,
      SMask: expect.any(PDFReference)
    });

    expect(img.obj.data.SMask.data).toMatchObject({
      BitsPerComponent: 8,
      ColorSpace: 'DeviceGray',
      Decode: [0, 1],
      Filter: 'FlateDecode',
      Height: 112,
      Length: 16,
      Subtype: 'Image',
      Type: 'XObject',
      Width: 112
    });
  });

  test('Interlaced grayscale', () => {
    // ImageWidth = 32
    // ImageHeight = 32
    // BitDepth = 8
    // ColorType = 0
    // Compression = 0
    // Filter = 0
    // Interlace = 1

    const img = createImage('./tests/images/interlaced-grayscale-8bit.png');

    expect(img.finalize).toBeCalledTimes(1);

    expect(img.obj.data).toMatchObject({
      BitsPerComponent: 8,
      ColorSpace: 'DeviceGray',
      Filter: 'FlateDecode',
      Height: 32,
      Length: 181,
      Subtype: 'Image',
      Type: 'XObject',
      Width: 32,
      DecodeParms: expect.any(PDFReference)
    });

    expect(img.obj.data.DecodeParms.data).toMatchObject({
      BitsPerComponent: 8,
      Colors: 1,
      Columns: 32,
      Predictor: 1
    });
  });

  test('Interlaced pallete', () => {
    // ImageWidth = 32
    // ImageHeight = 32
    // BitDepth = 8
    // ColorType = 3
    // Compression = 0
    // Filter = 0
    // Interlace = 1

    const img = createImage('./tests/images/interlaced-pallete-8bit.png');

    expect(img.finalize).toBeCalledTimes(1);

    expect(img.obj.data).toMatchObject({
      BitsPerComponent: 8,
      ColorSpace: ['Indexed', 'DeviceRGB', 255, expect.any(PDFReference)],
      Filter: 'FlateDecode',
      Height: 32,
      Length: 674,
      Subtype: 'Image',
      Type: 'XObject',
      Width: 32,
      DecodeParms: expect.any(PDFReference)
    });

    expect(img.obj.data.DecodeParms.data).toMatchObject({
      BitsPerComponent: 8,
      Colors: 1,
      Columns: 32,
      Predictor: 1
    });
  });

  test('Interlaced RGB (8bit)', () => {
    // ImageWidth = 32
    // ImageHeight = 32
    // BitDepth = 8
    // ColorType = 2
    // Compression = 0
    // Filter = 0
    // Interlace = 1

    const img = createImage('./tests/images/interlaced-rgb-8bit.png');

    expect(img.finalize).toBeCalledTimes(1);

    expect(img.obj.data).toMatchObject({
      BitsPerComponent: 8,
      ColorSpace: 'DeviceRGB',
      Filter: 'FlateDecode',
      Height: 32,
      Length: 242,
      Subtype: 'Image',
      Type: 'XObject',
      Width: 32,
      DecodeParms: expect.any(PDFReference)
    });

    expect(img.obj.data.DecodeParms.data).toMatchObject({
      BitsPerComponent: 8,
      Colors: 3,
      Columns: 32,
      Predictor: 1
    });
  });

  test('Interlaced RGB (16bit)', () => {
    // ImageWidth = 32
    // ImageHeight = 32
    // BitDepth = 16
    // ColorType = 2
    // Compression = 0
    // Filter = 0
    // Interlace = 1

    const img = createImage('./tests/images/interlaced-rgb-16bit.png');

    expect(img.finalize).toBeCalledTimes(1);

    expect(img.obj.data).toMatchObject({
      BitsPerComponent: 16,
      ColorSpace: 'DeviceRGB',
      Filter: 'FlateDecode',
      Height: 32,
      Length: 522,
      Subtype: 'Image',
      Type: 'XObject',
      Width: 32,
      DecodeParms: expect.any(PDFReference)
    });

    expect(img.obj.data.DecodeParms.data).toMatchObject({
      BitsPerComponent: 16,
      Colors: 3,
      Columns: 32,
      Predictor: 1
    });
  });

  test('Interlaced RGB with alpha', () => {
    // ImageWidth = 32
    // ImageHeight = 32
    // BitDepth = 8
    // ColorType = 6
    // Compression = 0
    // Filter = 0
    // Interlace = 1

    const img = createImage('./tests/images/interlaced-rgb-alpha-8bit.png');

    expect(img.finalize).toBeCalledTimes(1);

    expect(img.obj.data).toMatchObject({
      BitsPerComponent: 8,
      ColorSpace: 'DeviceRGB',
      Filter: 'FlateDecode',
      Height: 32,
      Length: 288,
      Subtype: 'Image',
      Type: 'XObject',
      Width: 32,
      SMask: expect.any(PDFReference)
    });
  });
});