//-----------------------------------------------------------------------------
// Description:
// This example shows how to scale the value channel of an image. This is
// a potential way to implement an auto-contrast/auto-levels operation
//-----------------------------------------------------------------------------
void LevelScalingWithClipping()
{
CHistLib Histogram;
// Open the image
Mat ImageLowContrast = imread("images/fiveShadesLowContrast.png");
assert(!ImageLowContrast.empty());
Mat ImageLowContrastClipped;
// Perform the normalized clipping procedure
double clipPercent = 50;
Histogram.NormalizeClipImageBGR(ImageLowContrast, ImageLowContrastClipped, clipPercent);
Mat HistImageLowContrastClipped;
Histogram.ComputeAndDrawHistogramValue(ImageLowContrastClipped, HistImageLowContrastClipped);
// Save the modified image
string ImageLowContrastClippedName("fiveShadesLowContrastClipped.value.png");
if (imwrite(ImageLowContrastClippedName, ImageLowContrastClipped))
{
cout << "Created clipped image: " << ImageLowContrastClippedName << endl;
}
// Save the histogram image
string HistImageLowContrastClippedName("fiveShadesLowContrastClipped.value.hist.png");
if (imwrite(HistImageLowContrastClippedName, HistImageLowContrastClipped))
{
cout << "Created value histogram: " << HistImageLowContrastClippedName << endl;
}
}
//-----------------------------------------------------------------------------
// Description:
// This example shows how to scale the value channel of an image. This is
// a potential way to implement an auto-contrast/auto-levels operation
//-----------------------------------------------------------------------------
void LevelScalingLowContrast()
{
CHistLib Histogram;
// Open the image
Mat ImageLowContrast = imread("images/fiveShadesLowContrast.png");
assert(!ImageLowContrast.empty());
Mat ImageOriginalNorm;
Mat ImageLowContrastNorm;
// Generate color histogram for the current image
Mat HistImageGray;
Histogram.NormalizeImageBGR(ImageLowContrast, ImageLowContrastNorm);
Mat HistImageLowContrast;
Mat HistImageLowContrastNorm;
Histogram.ComputeAndDrawHistogramValue(ImageLowContrast, HistImageLowContrast);
Histogram.ComputeAndDrawHistogramValue(ImageLowContrastNorm, HistImageLowContrastNorm);
// Save the histogram images
string HistImageLowContrastName("fiveShadesLowContrast.value.hist.png");
string HistImageLowContrastNormName("fiveShadesLowContrastNorm.value.hist.png");
string ImageLowContrastNormName("fiveShadesLowContrastNorm.png");
if (imwrite(HistImageLowContrastName, HistImageLowContrast))
{
cout << "Created value histogram: " << HistImageLowContrastName << endl;
}
if (imwrite(HistImageLowContrastNormName, HistImageLowContrastNorm))
{
cout << "Created value histogram: " << HistImageLowContrastNormName << endl;
}
if (imwrite(ImageLowContrastNormName, ImageLowContrastNorm))
{
cout << "Created normalized image: " << ImageLowContrastNormName << endl;
}
}
//-----------------------------------------------------------------------------
// Description:
// This example shows how to scale the value channel of an image. This is
// a potential way to implement an auto-contrast/auto-levels operation
//-----------------------------------------------------------------------------
void LevelScalingNoEffect()
{
CHistLib Histogram;
// Open the image
Mat ImageOriginal = imread("images/fiveShades.png");
assert(!ImageOriginal.empty());
Mat ImageOriginalNorm;
// Generate color histogram for the current image
Mat HistImageGray;
// Used to verify that this operation does not modify the original image
Histogram.NormalizeImageBGR(ImageOriginal, ImageOriginalNorm);
Mat HistImageOriginal;
Mat HistImageOriginalNorm;
Histogram.ComputeAndDrawHistogramValue(ImageOriginal, HistImageOriginal);
Histogram.ComputeAndDrawHistogramValue(ImageOriginalNorm, HistImageOriginalNorm);
// Save the histogram images
string HistImageOriginalName("fiveShades.value.hist.png");
string HistImageOriginalNormName("fiveShadesNorm.value.hist.png");
if (imwrite(HistImageOriginalName, HistImageOriginal))
{
cout << "Created value histogram: " << HistImageOriginalName << endl;
}
if (imwrite(HistImageOriginalNormName, HistImageOriginalNorm))
{
cout << "Created value histogram: " << HistImageOriginalNormName << endl;
}
}
//-----------------------------------------------------------------------------
// Description:
// This example draws a value histogram from a test image.
//-----------------------------------------------------------------------------
void DrawSimpleValueHistogram()
{
CHistLib Histogram;
// Open the image
Mat ImageBGR = imread("images/bars.png");
assert(!ImageBGR.empty());
// Generate color histogram for the current image
Mat HistImageGray;
Histogram.ComputeAndDrawHistogramValue(ImageBGR, HistImageGray);
// Save the histogram image
string ImageName("bars.value.hist.png");
if (imwrite(ImageName, HistImageGray))
{
cout << "Created value histogram: " << ImageName << endl;
}
}