00001 #include "EdgeDetection/AdaptiveRasterizer.h"
00002
00003 #include "EdgeDetection/OwnedImage.h"
00004
00005 namespace EdgeDetection
00006 {
00007 Image* AdaptiveRasterizer::Rasterize(Rasterizable* object, int width, int height)
00008 {
00009 if (object == 0) throw "The parameter 'object' cannot be NULL.";
00010 if (width < 0) throw "The parameter 'threshold' was out of range.";
00011 if (height < 0) throw "The parameter 'threshold' was out of range.";
00012
00013 OwnedImage* image = new OwnedImage(width, height);
00014
00015 Rectangle region = object->GetRegion();
00016
00017 double pixelWidth = region.GetWidth() / width;
00018 double pixelHeight = region.GetHeight() / height;
00019
00020 for (int y = 0; y < height; y++)
00021 for (int x = 0; x < width; x++)
00022 {
00023 double left = region.GetLeft() + (x + 0) * pixelWidth;
00024 double right = region.GetLeft() + (x + 1) * pixelWidth;
00025 double top = region.GetTop() + (y + 0) * pixelHeight;
00026 double bottom = region.GetTop() + (y + 1) * pixelHeight;
00027
00028 double value = GetValue(object, Rectangle(left, right, top, bottom));
00029
00030 image->Set(x, y, value);
00031 }
00032
00033 return image;
00034 }
00035
00036 double AdaptiveRasterizer::GetValue(Rasterizable* object, Rectangle rectangle)
00037 {
00038 if (object->CanCalculateIntegral(rectangle)) return object->CalculateIntegral(rectangle);
00039 if (rectangle.GetArea() < threshold) return object->EstimateIntegral(rectangle);
00040
00041 Rectangle leftTop = Rectangle(rectangle.GetLeft(), rectangle.GetCenter().GetX(), rectangle.GetTop(), rectangle.GetCenter().GetY());
00042 Rectangle rightTop = Rectangle(rectangle.GetCenter().GetX(), rectangle.GetRight(), rectangle.GetTop(), rectangle.GetCenter().GetY());
00043 Rectangle leftBottom = Rectangle(rectangle.GetLeft(), rectangle.GetCenter().GetX(), rectangle.GetCenter().GetY(), rectangle.GetBottom());
00044 Rectangle rightBottom = Rectangle(rectangle.GetCenter().GetX(), rectangle.GetRight(), rectangle.GetCenter().GetY(), rectangle.GetBottom());
00045
00046 return GetValue(object, leftTop) + GetValue(object, rightTop) + GetValue(object, leftBottom) + GetValue(object, rightBottom);
00047 }
00048 };
