@zxing/library
Version:
TypeScript port of ZXing multi-format 1D/2D barcode image processing library.
72 lines (71 loc) • 2.9 kB
TypeScript
import ResultPoint from '../../ResultPoint';
import BitMatrix from '../BitMatrix';
/**
* <p>
* Detects a candidate barcode-like rectangular region within an image. It
* starts around the center of the image, increases the size of the candidate
* region until it finds a white rectangular region. By keeping track of the
* last black points it encountered, it determines the corners of the barcode.
* </p>
*
* @author David Olivier
*/
export default class WhiteRectangleDetector {
private image;
private static INIT_SIZE;
private static CORR;
private height;
private width;
private leftInit;
private rightInit;
private downInit;
private upInit;
/**
* @param image barcode image to find a rectangle in
* @param initSize initial size of search area around center
* @param x x position of search center
* @param y y position of search center
* @throws NotFoundException if image is too small to accommodate {@code initSize}
*/
constructor(image: BitMatrix, initSize?: number, x?: number, y?: number);
/**
* <p>
* Detects a candidate barcode-like rectangular region within an image. It
* starts around the center of the image, increases the size of the candidate
* region until it finds a white rectangular region.
* </p>
*
* @return {@link ResultPoint}[] describing the corners of the rectangular
* region. The first and last points are opposed on the diagonal, as
* are the second and third. The first point will be the topmost
* point and the last, the bottommost. The second point will be
* leftmost and the third, the rightmost
* @throws NotFoundException if no Data Matrix Code can be found
*/
detect(): Array<ResultPoint>;
private getBlackPointOnSegment;
/**
* recenters the points of a constant distance towards the center
*
* @param y bottom most point
* @param z left most point
* @param x right most point
* @param t top most point
* @return {@link ResultPoint}[] describing the corners of the rectangular
* region. The first and last points are opposed on the diagonal, as
* are the second and third. The first point will be the topmost
* point and the last, the bottommost. The second point will be
* leftmost and the third, the rightmost
*/
private centerEdges;
/**
* Determines whether a segment contains a black point
*
* @param a min value of the scanned coordinate
* @param b max value of the scanned coordinate
* @param fixed value of fixed coordinate
* @param horizontal set to true if scan must be horizontal, false if vertical
* @return true if a black point has been found, else false.
*/
private containsBlackPoint;
}