Package-level declarations

A simple, fast array of bits, represented compactly by an array of ints internally.

Represents a 2D matrix of bits. In function arguments below, and throughout the common module, x is the column position, and y is the row position. The ordering is always x, y. The origin is at the top-left.

This provides an easy abstraction to read bits at a time from a sequence of bytes, where the number of bits read is not often a multiple of 8.

Encapsulates a Character Set ECI, according to "Extended Channel Interpretations" 5.3.1.1 of ISO 18004.

Encapsulates the result of decoding a matrix of bits. This typically applies to 2D barcode formats. For now it contains the raw bytes obtained, as well as a String interpretation of those bytes, if applicable.

Encapsulates the result of detecting a barcode in an image. This includes the raw matrix of black/white pixels corresponding to the barcode, and possibly points of interest in the image, like the location of finder patterns or corners of the barcode in the image.

Set of CharsetEncoders for a given input string

Interface to navigate a sequence of ECIs and bytes.

Class that converts a sequence of ECIs and bytes into a string

This Binarizer implementation uses the old ZXing global histogram approach. It is suitable for low-end mobile devices which don't have enough CPU or memory to use a local thresholding algorithm. However, because it picks a global black point, it cannot handle difficult shadows and gradients.

Implementations of this class can, given locations of finder patterns for a QR code in an image, sample the right points in the image to reconstruct the QR code, accounting for perspective distortion. It is abstracted since it is relatively expensive and should be allowed to take advantage of platform-specific optimized implementations, like Sun's Java Advanced Imaging library, but which may not be available in other environments such as J2ME, and vice versa.

This class implements a local thresholding algorithm, which while slower than the GlobalHistogramBinarizer, is fairly efficient for what it does. It is designed for high frequency images of barcodes with black data on white backgrounds. For this application, it does a much better job than a global blackpoint with severe shadows and gradients. However it tends to produce artifacts on lower frequency images and is therefore not a good general purpose binarizer for uses outside ZXing.

Class that converts a character string into a sequence of ECIs and bytes

This class implements a perspective transform in two dimensions. Given four source and four destination points, it will compute the transformation implied between them. The code is based directly upon section 3.4.2 of George Wolberg's "Digital Image Warping"; see pages 54-56.

Common string-related functions.