Mercurial > hgrepos > Python2 > PyMuPDF
comparison mupdf-source/thirdparty/zxing-cpp/core/src/GridSampler.cpp @ 2:b50eed0cc0ef upstream
ADD: MuPDF v1.26.7: the MuPDF source as downloaded by a default build of PyMuPDF 1.26.4.
The directory name has changed: no version number in the expanded directory now.
| author | Franz Glasner <fzglas.hg@dom66.de> |
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| date | Mon, 15 Sep 2025 11:43:07 +0200 |
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| 1:1d09e1dec1d9 | 2:b50eed0cc0ef |
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| 1 /* | |
| 2 * Copyright 2016 Nu-book Inc. | |
| 3 * Copyright 2016 ZXing authors | |
| 4 * Copyright 2020 Axel Waggershauser | |
| 5 */ | |
| 6 // SPDX-License-Identifier: Apache-2.0 | |
| 7 | |
| 8 #include "GridSampler.h" | |
| 9 | |
| 10 #ifdef PRINT_DEBUG | |
| 11 #include "LogMatrix.h" | |
| 12 #include "BitMatrixIO.h" | |
| 13 #endif | |
| 14 | |
| 15 namespace ZXing { | |
| 16 | |
| 17 #ifdef PRINT_DEBUG | |
| 18 LogMatrix log; | |
| 19 #endif | |
| 20 | |
| 21 DetectorResult SampleGrid(const BitMatrix& image, int width, int height, const PerspectiveTransform& mod2Pix) | |
| 22 { | |
| 23 return SampleGrid(image, width, height, {ROI{0, width, 0, height, mod2Pix}}); | |
| 24 } | |
| 25 | |
| 26 DetectorResult SampleGrid(const BitMatrix& image, int width, int height, const ROIs& rois) | |
| 27 { | |
| 28 #ifdef PRINT_DEBUG | |
| 29 LogMatrix log; | |
| 30 static int i = 0; | |
| 31 LogMatrixWriter lmw(log, image, 5, "grid" + std::to_string(i++) + ".pnm"); | |
| 32 #endif | |
| 33 if (width <= 0 || height <= 0) | |
| 34 return {}; | |
| 35 | |
| 36 for (auto&& [x0, x1, y0, y1, mod2Pix] : rois) { | |
| 37 // Precheck the corners of every roi to bail out early if the grid is "obviously" not completely inside the image | |
| 38 auto isInside = [&mod2Pix = mod2Pix, &image](int x, int y) { return image.isIn(mod2Pix(centered(PointI(x, y)))); }; | |
| 39 if (!mod2Pix.isValid() || !isInside(x0, y0) || !isInside(x1 - 1, y0) || !isInside(x1 - 1, y1 - 1) || !isInside(x0, y1 - 1)) | |
| 40 return {}; | |
| 41 } | |
| 42 | |
| 43 BitMatrix res(width, height); | |
| 44 for (auto&& [x0, x1, y0, y1, mod2Pix] : rois) { | |
| 45 for (int y = y0; y < y1; ++y) | |
| 46 for (int x = x0; x < x1; ++x) { | |
| 47 auto p = mod2Pix(centered(PointI{x, y})); | |
| 48 // Due to a "numerical instability" in the PerspectiveTransform generation/application it has been observed | |
| 49 // that even though all boundary grid points get projected inside the image, it can still happen that an | |
| 50 // inner grid points is not. See #563. A true perspective transformation cannot have this property. | |
| 51 // The following check takes 100% care of the issue and turned out to be less of a performance impact than feared. | |
| 52 // TODO: Check some mathematical/numercial property of mod2Pix to determine if it is a perspective transforation. | |
| 53 if (!image.isIn(p)) | |
| 54 return {}; | |
| 55 | |
| 56 #ifdef PRINT_DEBUG | |
| 57 log(p, 3); | |
| 58 #endif | |
| 59 #if 0 | |
| 60 int sum = 0; | |
| 61 for (int dy = -1; dy <= 1; ++dy) | |
| 62 for (int dx = -1; dx <= 1; ++dx) | |
| 63 sum += image.get(p + PointF(dx, dy)); | |
| 64 if (sum >= 5) | |
| 65 #else | |
| 66 if (image.get(p)) | |
| 67 #endif | |
| 68 res.set(x, y); | |
| 69 } | |
| 70 } | |
| 71 | |
| 72 #ifdef PRINT_DEBUG | |
| 73 printf("width: %d, height: %d\n", width, height); | |
| 74 // printf("%s", ToString(res).c_str()); | |
| 75 #endif | |
| 76 | |
| 77 auto projectCorner = [&](PointI p) { | |
| 78 for (auto&& [x0, x1, y0, y1, mod2Pix] : rois) | |
| 79 if (x0 <= p.x && p.x <= x1 && y0 <= p.y && p.y <= y1) | |
| 80 return PointI(mod2Pix(PointF(p)) + PointF(0.5, 0.5)); | |
| 81 | |
| 82 return PointI(); | |
| 83 }; | |
| 84 | |
| 85 return {std::move(res), | |
| 86 {projectCorner({0, 0}), projectCorner({width, 0}), projectCorner({width, height}), projectCorner({0, height})}}; | |
| 87 } | |
| 88 | |
| 89 } // ZXing |