Mercurial > hg > svgui
view layer/ImageRegionFinder.cpp @ 349:369a197737c7
* Various fixes to object lifetime management, particularly in the spectrum
layer and for notification of main model deletion.
The main purpose of this is to improve the behaviour of the spectrum, but I
think it may also help with #1840922 Various crashes in Layer Summary window.
author | Chris Cannam |
---|---|
date | Wed, 23 Jan 2008 15:43:27 +0000 |
parents | 86a112b5b319 |
children | 1a0dfcbffaf1 |
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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); // std::cerr << "thresh=" << thresh << ", dist=" << dist << std::endl; return (dist < thresh); }