Histogram equalization

Functions
VISP_EXPORT void	VISP_NAMESPACE_NAME::equalizeHistogram (VISP_NAMESPACE_ADDRESSING vpImage< unsigned char > &I, const VISP_NAMESPACE_ADDRESSING vpImage< bool > *p_mask=nullptr)
VISP_EXPORT void	VISP_NAMESPACE_NAME::equalizeHistogram (const VISP_NAMESPACE_ADDRESSING vpImage< unsigned char > &I1, VISP_NAMESPACE_ADDRESSING vpImage< unsigned char > &I2, const VISP_NAMESPACE_ADDRESSING vpImage< bool > *p_mask=nullptr)
VISP_EXPORT void	VISP_NAMESPACE_NAME::equalizeHistogram (VISP_NAMESPACE_ADDRESSING vpImage< VISP_NAMESPACE_ADDRESSING vpRGBa > &I, bool useHSV=false)
VISP_EXPORT void	VISP_NAMESPACE_NAME::equalizeHistogram (const VISP_NAMESPACE_ADDRESSING vpImage< VISP_NAMESPACE_ADDRESSING vpRGBa > &I1, VISP_NAMESPACE_ADDRESSING vpImage< VISP_NAMESPACE_ADDRESSING vpRGBa > &I2, bool useHSV=false)

Detailed Description

Histogram equalization.

Tutorials

If you are interested in histogram equalization techniques, you may have a look at

• Tutorial: Brightness and contrast adjustment
• Tutorial: Contrast and image sharpening techniques

Function Documentation

equalizeHistogram() [1/4]

VISP_EXPORT void VISP_NAMESPACE_NAME::equalizeHistogram	(	const VISP_NAMESPACE_ADDRESSING vpImage< unsigned char > &	I1,
		VISP_NAMESPACE_ADDRESSING vpImage< unsigned char > &	I2,
		const VISP_NAMESPACE_ADDRESSING vpImage< bool > *	p_mask = nullptr )

Adjust the contrast of a grayscale image by performing an histogram equalization. The intensity distribution is redistributed over the full [0 - 255] range such as the cumulative histogram distribution becomes linear.

Parameters

I1	: The first grayscale image.
I2	: The second grayscale image after histogram equalization.
p_mask	: If set, a boolean mask to take into account only the points for which the mask is true.

equalizeHistogram() [2/4]

VISP_EXPORT void VISP_NAMESPACE_NAME::equalizeHistogram	(	const VISP_NAMESPACE_ADDRESSING vpImage< VISP_NAMESPACE_ADDRESSING vpRGBa > &	I1,
		VISP_NAMESPACE_ADDRESSING vpImage< VISP_NAMESPACE_ADDRESSING vpRGBa > &	I2,
		bool	useHSV = false )

Adjust the contrast of a color image by performing an histogram equalization. The intensity distribution is redistributed over the full [0 - 255] range such as the cumulative histogram distribution becomes linear. The alpha channel is ignored / copied from the source alpha channel.

Parameters

I1	: The first color image.
I2	: The second color image after histogram equalization.
useHSV	: If true, the histogram equalization is performed on the value channel (in HSV space), otherwise the histogram equalization is performed independently on the RGB channels.

equalizeHistogram() [3/4]

VISP_EXPORT void VISP_NAMESPACE_NAME::equalizeHistogram	(	VISP_NAMESPACE_ADDRESSING vpImage< unsigned char > &	I,
		const VISP_NAMESPACE_ADDRESSING vpImage< bool > *	p_mask = nullptr )

Adjust the contrast of a grayscale image by performing an histogram equalization. The intensity distribution is redistributed over the full [0 - 255] range such as the cumulative histogram distribution becomes linear.

Parameters

I	: The grayscale image to apply histogram equalization.
p_mask	: If set, a boolean mask to take into account only the points for which the mask is true.

Examples

testImgproc.cpp, tutorial-brightness-adjustment.cpp, and tutorial-contrast-sharpening.cpp.

Referenced by equalizeHistogram(), equalizeHistogram(), and equalizeHistogram().

equalizeHistogram() [4/4]

VISP_EXPORT void VISP_NAMESPACE_NAME::equalizeHistogram	(	VISP_NAMESPACE_ADDRESSING vpImage< VISP_NAMESPACE_ADDRESSING vpRGBa > &	I,
		bool	useHSV = false )

Adjust the contrast of a color image by performing an histogram equalization. The intensity distribution is redistributed over the full [0 - 255] range such as the cumulative histogram distribution becomes linear. The alpha channel is ignored / copied from the source alpha channel.

Parameters

I	: The color image to apply histogram equalization.
useHSV	: If true, the histogram equalization is performed on the value channel (in HSV space), otherwise the histogram equalization is performed independently on the RGB channels.