hyperion.ng/libsrc/hyperion/BlackBorderDetector.cpp
T. van der Zwan f262a9eb11 Updated the scan-algorithm to only use half of each border.
Added doxygen comments to the header file.
2013-08-21 14:52:03 +00:00

107 lines
1.9 KiB
C++

#include "BlackBorderDetector.h"
BlackBorderDetector::BlackBorderDetector()
{
// empty
}
BlackBorder BlackBorderDetector::process(const RgbImage& image)
{
int firstNonBlackPixelTop = -1;
int firstNonBlackPixelLeft = -1;
// Find the non-black pixel at the top-half border
for (unsigned x=0; x<image.width()/2; ++x)
{
const RgbColor& color = image(x, 0);
if (!isBlack(color))
{
firstNonBlackPixelTop = x;
break;
}
}
// Find the non-black pixel at the left-half border
for (unsigned y=0; y<image.height()/2; ++y)
{
const RgbColor& color = image(0, y);
if (!isBlack(color))
{
firstNonBlackPixelLeft = y;
break;
}
}
// Construct 'unknown' result
BlackBorder detectedBorder;
detectedBorder.type = BlackBorder::unknown;
if (firstNonBlackPixelTop == 0 /*&& firstNonBlackPixelLeft == 0*/)
{
// No black border
// C-?-?-? ...
// ? +----
// ? |
// ? |
// :
detectedBorder.type = BlackBorder::none;
detectedBorder.size = -1;
}
else if (firstNonBlackPixelTop < 0)
{
if (firstNonBlackPixelLeft < 0)
{
// We don't know
// B-B-B-B ...
// B +---- ...
// B |
// B |
// :
detectedBorder.type = BlackBorder::unknown;
detectedBorder.size = -1;
}
else //(firstNonBlackPixelLeft > 0)
{
// Border at top of screen
// B-B-B-B ...
// B +---- ...
// C |
// ? |
// :
detectedBorder.type = BlackBorder::horizontal;
detectedBorder.size = firstNonBlackPixelLeft;
}
}
else // (firstNonBlackPixelTop > 0)
{
if (firstNonBlackPixelLeft < 0)
{
// Border at left of screen
// B-B-C-? ...
// B +---- ...
// B |
// B |
// :
detectedBorder.type = BlackBorder::vertical;
detectedBorder.size = firstNonBlackPixelTop;
}
else //(firstNonBlackPixelLeft > 0)
{
// No black border
// B-B-C-? ...
// B +----
// C |
// ? |
// :
detectedBorder.type = BlackBorder::none;
detectedBorder.size = -1;
}
}
return detectedBorder;
}