Constructor Detail

• FingerprintImage

  public FingerprintImage()

  Creates new container for fingerprint image data. The newly constructed instance cannot be used to create FingerprintTemplate until at least pixel data is provided by calling decode(byte[]) or grayscale(int, int, byte[]).

  See Also:

  decode(byte[]), grayscale(int, int, byte[])

Method Detail

• dpi

  public FingerprintImage dpi(double dpi)

  Sets DPI (dots per inch) of the fingerprint image. This is the DPI of the image passed to decode(byte[]) or grayscale(int, int, byte[]). Check your fingerprint reader specification for correct DPI value. Default DPI is 500.

  Parameters:

  dpi - DPI of the fingerprint image, usually around 500

  Returns:

  this (fluent method)

  Throws:

  IllegalArgumentException - if dpi is non-positive, impossibly low, or impossibly high

  See Also:

  decode(byte[])

• decode

  public FingerprintImage decode(byte[] image)

  Decodes fingerprint image in standard format. The image must contain black fingerprint on white background at the DPI specified by calling dpi(double).

  The image may be in any format commonly used to store fingerprint images, including PNG, JPEG, BMP, TIFF, or WSQ. SourceAFIS will try to decode the image using Java's ImageIO (PNG, JPEG, BMP), Sanselan library (TIFF), JNBIS library (WSQ), and Android's Bitmap class (PNG, JPEG, BMP) in this order. Note that these libraries might not support all versions and variations of the mentioned formats.

  Parameters:

  image - fingerprint image in one of the supported formats

  Returns:

  this (fluent method)

  Throws:

  NullPointerException - if image is null

  IllegalArgumentException - if the image format is unsupported or the image is corrupted

  See Also:

  dpi(double), grayscale(int, int, byte[]), FingerprintCompatibility.convert(byte[]), FingerprintTemplate.FingerprintTemplate(byte[])

• grayscale

  public FingerprintImage grayscale(int width,
                                    int height,
                                    byte[] pixels)

  Reads raw grayscale fingerprint image from byte array. The image must contain black fingerprint on white background at the DPI specified by calling dpi(double).

  Pixels are represented as 8-bit unsigned bytes with 0 meaning black and 255 meaning white. Java's byte is a signed 8-bit number, but this method interprets all 8 bits as an unsigned number as if by calling Byte.toUnsignedInt(byte). Pixels in pixels array are ordered from top-left to bottom-right in horizontal rows. Size of pixels must be equal to width * height.

  Parameters:

  width - width of the image

  height - height of the image

  pixels - image pixels ordered from top-left to bottom-right in horizontal rows

  Returns:

  this (fluent method)

  Throws:

  NullPointerException - if image is null

  IndexOutOfBoundsException - if width or height is not positive or if pixels length is not width * height

  See Also:

  dpi(double), decode(byte[])