/* * Copyright 2007 ZXing authors * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ // package com.google.zxing.common; // import com.google.zxing.NotFoundException; use crate::{common::Result, Point}; use crate::{point_f, Exceptions}; use super::{BitMatrix, PerspectiveTransform, Quadrilateral}; /** * 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. * * The implementation used can be controlled by calling {@link #setGridSampler(GridSampler)} * with an instance of a class which implements this interface. * * @author Sean Owen */ pub trait GridSampler { // /** // * Sets the implementation of GridSampler used by the library. One global // * instance is stored, which may sound problematic. But, the implementation provided // * ought to be appropriate for the entire platform, and all uses of this library // * in the whole lifetime of the JVM. For instance, an Android activity can swap in // * an implementation that takes advantage of native platform libraries. // * // * @param newGridSampler The platform-specific object to install. // */ // public static void setGridSampler(GridSampler newGridSampler) { // gridSampler = newGridSampler; // } // /** // * @return the current implementation of GridSampler // */ // public static GridSampler getInstance() { // return gridSampler; // } /** * Samples an image for a rectangular matrix of bits of the given dimension. The sampling * transformation is determined by the coordinates of 4 points, in the original and transformed * image space. * * @param image image to sample * @param dimensionX width of {@link BitMatrix} to sample from image * @param dimensionY height of {@link BitMatrix} to sample from image * @param p1ToX point 1 preimage X * @param p1ToY point 1 preimage Y * @param p2ToX point 2 preimage X * @param p2ToY point 2 preimage Y * @param p3ToX point 3 preimage X * @param p3ToY point 3 preimage Y * @param p4ToX point 4 preimage X * @param p4ToY point 4 preimage Y * @param p1FromX point 1 image X * @param p1FromY point 1 image Y * @param p2FromX point 2 image X * @param p2FromY point 2 image Y * @param p3FromX point 3 image X * @param p3FromY point 3 image Y * @param p4FromX point 4 image X * @param p4FromY point 4 image Y * @return {@link BitMatrix} representing a grid of points sampled from the image within a region * defined by the "from" parameters * @throws NotFoundException if image can't be sampled, for example, if the transformation defined * by the given points is invalid or results in sampling outside the image boundaries */ #[allow(clippy::too_many_arguments)] fn sample_grid_detailed( &self, image: &BitMatrix, dimensionX: u32, dimensionY: u32, dst: Quadrilateral, src: Quadrilateral, ) -> Result<(BitMatrix, [Point; 4])> { let transform = PerspectiveTransform::quadrilateralToQuadrilateral(dst, src)?; self.sample_grid( image, dimensionX, dimensionY, &[SamplerControl::new(dimensionX, dimensionY, transform)], ) } fn sample_grid( &self, image: &BitMatrix, dimensionX: u32, dimensionY: u32, controls: &[SamplerControl], ) -> Result<(BitMatrix, [Point; 4])> { if dimensionX == 0 || dimensionY == 0 { return Err(Exceptions::NOT_FOUND); } let mut bits = BitMatrix::new(dimensionX, dimensionY)?; let mut points = vec![Point::default(); dimensionX as usize]; for y in 0..dimensionY { // for (int y = 0; y < dimensionY; y++) { let max = points.len(); let i_value = y as f32 + 0.5; let mut x = 0; while x < max { // for (int x = 0; x < max; x += 2) { points[x].x = (x as f32) + 0.5; points[x].y = i_value; x += 1; } controls .first() .unwrap() .transform .transform_points_single(&mut points); // Quick check to see if points transformed to something inside the image; // sufficient to check the endpoints self.checkAndNudgePoints(image, &mut points)?; // try { let mut x = 0; while x < max { // for (int x = 0; x < max; x += 2) { // if points[x] as u32 >= image.getWidth() || points[x + 1] as u32 >= image.getHeight() // { // return Err(Exceptions::notFound( // "index out of bounds, see documentation in file for explanation".to_owned(), // )); // } if image .try_get(points[x].x as u32, points[x].y as u32) .ok_or(Exceptions::not_found_with( "index out of bounds, see documentation in file for explanation", ))? { // Black(-ish) pixel bits.set(x as u32, y); } x += 1; } // } catch (ArrayIndexOutOfBoundsException aioobe) { // // This feels wrong, but, sometimes if the finder patterns are misidentified, the resulting // // transform gets "twisted" such that it maps a straight line of points to a set of points // // whose endpoints are in bounds, but others are not. There is probably some mathematical // // way to detect this about the transformation that I don't know yet. // // This results in an ugly runtime exception despite our clever checks above -- can't have // // that. We could check each point's coordinates but that feels duplicative. We settle for // // catching and wrapping ArrayIndexOutOfBoundsException. // throw NotFoundException.getNotFoundInstance(); // } } // dbg!(bits.to_string()); Ok(( bits, [ Point::default();4 ], )) } /** *

Checks a set of points that have been transformed to sample points on an image against * the image's dimensions to see if the point are even within the image.

* *

This method will actually "nudge" the endpoints back onto the image if they are found to be * barely (less than 1 pixel) off the image. This accounts for imperfect detection of finder * patterns in an image where the QR Code runs all the way to the image border.

* *

For efficiency, the method will check points from either end of the line until one is found * to be within the image. Because the set of points are assumed to be linear, this is valid.

* * @param image image into which the points should map * @param points actual points in x1,y1,...,xn,yn form * @throws NotFoundException if an endpoint is lies outside the image boundaries */ fn checkAndNudgePoints(&self, image: &BitMatrix, points: &mut [Point]) -> Result<()> { let width = image.getWidth(); let height = image.getHeight(); // Check and nudge points from start until we see some that are OK: let mut nudged = true; let max_offset = points.len() - 1; // points.length must be even let mut offset = 0; while offset < max_offset && nudged { // for (int offset = 0; offset < maxOffset && nudged; offset += 2) { let x = points[offset].x as i32; let y = points[offset].y as i32; if x < -1 || x > width as i32 || y < -1 || y > height as i32 { return Err(Exceptions::NOT_FOUND); } nudged = false; if x == -1 { points[offset].x = 0.0; nudged = true; } else if x == width as i32 { points[offset].x = width as f32 - 1.0; nudged = true; } if y == -1 { points[offset].y = 0.0; nudged = true; } else if y == height as i32 { points[offset].y = height as f32 - 1.0; nudged = true; } offset += 1; } // Check and nudge points from end: nudged = true; let mut offset = points.len() as isize - 1; while offset >= 0 && nudged { // for (int offset = points.length - 2; offset >= 0 && nudged; offset -= 2) { let x = points[offset as usize].x as i32; let y = points[offset as usize].y as i32; if x < -1 || x > width as i32 || y < -1 || y > height as i32 { return Err(Exceptions::NOT_FOUND); } nudged = false; if x == -1 { points[offset as usize].x = 0.0; nudged = true; } else if x == width as i32 { points[offset as usize].x = width as f32 - 1.0; nudged = true; } if y == -1 { points[offset as usize].y = 0.0; nudged = true; } else if y == height as i32 { points[offset as usize].y = height as f32 - 1.0; nudged = true; } offset += -1; } Ok(()) } } pub struct SamplerControl { pub p0: Point, pub p1: Point, pub transform: PerspectiveTransform, } impl SamplerControl { pub fn new(width: u32, height: u32, transform: PerspectiveTransform) -> Self { Self { p0: point_f(0.0, 0.0), p1: point_f(width as f32, height as f32), transform, } } }