Mercurial > hg > svgui
view layer/ImageRegionFinder.cpp @ 1584:e5464dc2f6cf
Add optional context menu to AudioDial
author | Chris Cannam |
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date | Thu, 26 Mar 2020 12:10:55 +0000 |
parents | b66fb15de477 |
children |
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/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */ /* Sonic Visualiser An audio file viewer and annotation editor. Centre for Digital Music, Queen Mary, University of London. This file copyright 2007 QMUL. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. See the file COPYING included with this distribution for more information. */ #include "ImageRegionFinder.h" #include <QImage> #include <cmath> #include <stack> #include <iostream> ImageRegionFinder::ImageRegionFinder() { } ImageRegionFinder::~ImageRegionFinder() { } QRect ImageRegionFinder::findRegionExtents(QImage *image, QPoint origin) const { int w = image->width(), h = image->height(); QImage visited(w, h, QImage::Format_Mono); visited.fill(0); std::stack<QPoint> s; s.push(origin); int xmin = origin.x(); int xmax = xmin; int ymin = origin.y(); int ymax = ymin; QRgb opix = image->pixel(origin); while (!s.empty()) { QPoint p = s.top(); s.pop(); visited.setPixel(p, 1); int x = p.x(), y = p.y(); if (x < xmin) xmin = x; if (x > xmax) xmax = x; if (y < ymin) ymin = y; if (y > ymax) ymax = y; std::stack<QPoint> neighbours; int similarNeighbourCount = 0; for (int dx = -1; dx <= 1; ++dx) { for (int dy = -1; dy <= 1; ++dy) { if ((dx != 0 && dy != 0) || (dx == 0 && dy == 0)) continue; if (x + dx < 0 || x + dx >= w || y + dy < 0 || y + dy >= h) continue; if (visited.pixelIndex(x + dx, y + dy) != 0) continue; if (!similar(opix, image->pixel(x + dx, y + dy))) continue; neighbours.push(QPoint(x + dx, y + dy)); ++similarNeighbourCount; } } if (similarNeighbourCount >= 2) { while (!neighbours.empty()) { s.push(neighbours.top()); neighbours.pop(); } } } return QRect(xmin, ymin, xmax - xmin, ymax - ymin); } bool ImageRegionFinder::similar(QRgb a, QRgb b) const { if (b == qRgb(0, 0, 0) || b == qRgb(255, 255, 255)) { // black and white are boundary cases, don't compare similar // to anything -- not even themselves return false; } float ar = float(qRed(a)) / 255.f; float ag = float(qGreen(a)) / 255.f; float ab = float(qBlue(a)) / 255.f; float amag = sqrtf(ar * ar + ag * ag + ab * ab); float thresh = amag / 2; float dr = float(qRed(a) - qRed(b)) / 255.f; float dg = float(qGreen(a) - qGreen(b)) / 255.f; float db = float(qBlue(a) - qBlue(b)) / 255.f; float dist = sqrtf(dr * dr + dg * dg + db * db); // cerr << "thresh=" << thresh << ", dist=" << dist << endl; return (dist < thresh); }