This class implements various image obscuration techniques for the PPM image format. More...

#include <obscurationPPM.hpp>

Inheritance diagram for obscurationPPM:

Collaboration diagram for obscurationPPM:

Static Public Member Functions
static int	interpolate_color (int p11, int p21, int p12, int p22, float dx, float dy)
	Interpolates the color value of a pixel at a given position using bilinear interpolation.

static void	interpolate_bilinear (ImageBase &image, int &valR, int &valG, int &valB, float i, float j)
	Interpolates the color values of a pixel at a given position in an image using bilinear interpolation.

static void	bilinearRedim299 (ImageBase &image, ImageBase &o_image)
	Resizes an image to 299x299 pixels using bilinear interpolation.

static void	computeColorHist (ImageBase &image, int histR[256], int histG[256], int histB[256])
	Computes the histograms of the red, green, and blue color components of an image.

static void	compareImagesByHist (ImageBase &image1, ImageBase &image2)
	Compares the histograms of two images.

static void	generateGaussianKernel (std::vector< std::vector< float > > &kernel, int size, float sigma)
	Generates a Gaussian kernel for image blurring.

static void	gaussianBlur (ImageBase &image, ImageBase &o_image, int kernelSize, float sigma)
	Applies Gaussian blurring to an image using a given kernel size and standard deviation.

static void	averageBlurring (ImageBase &image, ImageBase &o_image, int regionSize)
	Applies average blurring to an image using a given region size.

static void	newAverageBlurring (ImageBase &image, std::vector< ImageBase > &o_images)
	Applies new average blurring to an image using a given number of images.

static void	areaScrambling (ImageBase &image, ImageBase &o_image, int start_i, int start_j, int area_h, int area_w)
	Applies area scrambling to an image using a given start position and area size.

static void	scrambling (ImageBase &image, ImageBase &o_image, int regionHeight, int regionWidth)
	Applies scrambling to an image using a given region size.

static void	areaAverager (ImageBase &image, ImageBase &o_image, int start_i, int start_j, int area_h, int area_w)
	Applies area averaging to an image using a given start position and area size.

static void	averageByRegion (ImageBase &image, ImageBase &o_image, int regionHeight, int regionWidth)
	Applies average by region to an image using a given region size.

static void	selectiveProgressiveEncryption (ImageBase &image, ImageBase o_images[8], bool MSBtoLSB)
	Applies selective progressive encryption to an image using a given encryption direction.

static void	selectiveIndividualEncryption (ImageBase &image, ImageBase o_images[8])
	Applies selective individual encryption to an image.

static void	selectiveGroupEncryption (ImageBase &image, ImageBase &o_image, int bitsGroup[8], int groupSize)
	Applies selective group encryption to an image using a given bit group and group size.

static double	computePSNR (ImageBase &image1, ImageBase &image2)
	Computes the peak signal-to-noise ratio (PSNR) between two images.

static void	computePSNRforAllAlterations (std::vector< double > &PSNRArray, const char *baseName, int i_min, int i_max, int step)
	Computes the PSNR for all alterations in a given range.

static void	writeDataOnTxt (std::vector< double > &data, std::string filename)
	Writes data to a text file.

static void	RGB2GREY (ImageBase &imColor, ImageBase &imGrey)
	Converts an RGB image to grayscale.

static double	computeImageMean (ImageBase &image)
	Computes the mean value of an image.

static double	computeSSIM (ImageBase &image1, ImageBase &image2)
	Computes the structural similarity index (SSIM) between two images.

Static Public Member Functions inherited from obscurationCommon
static void	genPRNS (unsigned int seq[8])
	Generate a random sequence of 8 bits.

static void	genBitsGroups (std::vector< std::vector< int > > &groups, int groupSize)
	Generate groups of bits.

static void	intVec2intArray (std::vector< int > &vec, int arr[8])
	Convert a vector of integers to an array of integers.

Detailed Description

This class implements various image obscuration techniques for the PPM image format.

subclass obscurationCommon

Author: Norman Hutte

Date: 6 March 2024

Member Function Documentation

◆ areaAverager()

void obscurationPPM::areaAverager	(	ImageBase &	image,
		ImageBase &	o_image,
		int	start_i,
		int	start_j,
		int	area_h,
		int	area_w )

static

Applies area averaging to an image using a given start position and area size.

Parameters

image	The input image.
o_image	The output image.
start_i	The vertical start position of the averaging area.
start_j	The horizontal start position of the averaging area.
area_h	The height of the averaging area.
area_w	The width of the averaging area.

Author: Norman Hutte

Date: 6 March 2024

◆ areaScrambling()

void obscurationPPM::areaScrambling	(	ImageBase &	image,
		ImageBase &	o_image,
		int	start_i,
		int	start_j,
		int	area_h,
		int	area_w )

static

Applies area scrambling to an image using a given start position and area size.

Parameters

image	The input image.
o_image	The output image.
start_i	The vertical start position of the scrambling area.
start_j	The horizontal start position of the scrambling area.
area_h	The height of the scrambling area.
area_w	The width of the scrambling area.

Author: Norman Hutte

Date: 6 March 2024

◆ averageBlurring()

void obscurationPPM::averageBlurring	(	ImageBase &	image,
		ImageBase &	o_image,
		int	regionSize )

static

Applies average blurring to an image using a given region size.

Parameters

image	The input image.
o_image	The output image.
regionSize	The size of the averaging region.

Author: Norman Hutte

Date: 6 March 2024

◆ averageByRegion()

void obscurationPPM::averageByRegion	(	ImageBase &	image,
		ImageBase &	o_image,
		int	regionHeight,
		int	regionWidth )

static

Applies average by region to an image using a given region size.

Parameters

image	The input image.
o_image	The output image.
regionHeight	The height of the averaging region.
regionWidth	The width of the averaging region.

Author: Norman Hutte

Date: 6 March 2024

◆ bilinearRedim299()

void obscurationPPM::bilinearRedim299	(	ImageBase &	image,
		ImageBase &	o_image )

static

Resizes an image to 299x299 pixels using bilinear interpolation.

Parameters

image	The input image.
o_image	The output image.

Author: Norman Hutte

Date: 6 March 2024

◆ compareImagesByHist()

void obscurationPPM::compareImagesByHist	(	ImageBase &	image1,
		ImageBase &	image2 )

static

Compares the histograms of two images.

Parameters

image1	The first image.
image2	The second image.

Author: Norman Hutte

Date: 6 March 2024

◆ computeColorHist()

void obscurationPPM::computeColorHist	(	ImageBase &	image,
		int	histR[256],
		int	histG[256],
		int	histB[256] )

static

Computes the histograms of the red, green, and blue color components of an image.

Parameters

image	The input image.
histR	The histogram of the red color component.
histG	The histogram of the green color component.
histB	The histogram of the blue color component.

Author: Norman Hutte

Date: 6 March 2024

◆ computeImageMean()

double obscurationPPM::computeImageMean ( ImageBase & image )

static

Computes the mean value of an image.

Parameters

image The input image.

Returns: The mean value.

Author: Norman Hutte

Date: 6 March 2024

◆ computePSNR()

double obscurationPPM::computePSNR	(	ImageBase &	image1,
		ImageBase &	image2 )

static

Computes the peak signal-to-noise ratio (PSNR) between two images.

Parameters

image1	The first image.
image2	The second image.

Returns: The PSNR value.

Author: Norman Hutte

Date: 6 March 2024

◆ computePSNRforAllAlterations()

void obscurationPPM::computePSNRforAllAlterations	(	std::vector< double > &	PSNRArray,
		const char *	baseName,
		int	i_min,
		int	i_max,
		int	step )

static

Computes the PSNR for all alterations in a given range.

Parameters

PSNRArray	The output array of PSNR values.
baseName	The base name of the input files.
i_min	The minimum alteration index.
i_max	The maximum alteration index.
step	The step size between alteration indices.

Author: Norman Hutte

Date: 6 March 2024

◆ computeSSIM()

double obscurationPPM::computeSSIM	(	ImageBase &	image1,
		ImageBase &	image2 )

static

Computes the structural similarity index (SSIM) between two images.

Parameters

image1	The first image.
image2	The second image.

Returns: The SSIM value.

Author: Norman Hutte

Date: 6 March 2024

◆ gaussianBlur()

void obscurationPPM::gaussianBlur	(	ImageBase &	image,
		ImageBase &	o_image,
		int	kernelSize,
		float	sigma )

static

Applies Gaussian blurring to an image using a given kernel size and standard deviation.

Parameters

image	The input image.
o_image	The output image.
kernelSize	The size of the Gaussian kernel.
sigma	The standard deviation of the Gaussian distribution.

Author: Norman Hutte

Date: 6 March 2024

◆ generateGaussianKernel()

void obscurationPPM::generateGaussianKernel	(	std::vector< std::vector< float > > &	kernel,
		int	size,
		float	sigma )

static

Generates a Gaussian kernel for image blurring.

Parameters

kernel	The output kernel.
size	The size of the kernel.
sigma	The standard deviation of the Gaussian distribution.

Author: Norman Hutte

Date: 6 March 2024

◆ interpolate_bilinear()

void obscurationPPM::interpolate_bilinear	(	ImageBase &	image,
		int &	valR,
		int &	valG,
		int &	valB,
		float	i,
		float	j )

static

Interpolates the color values of a pixel at a given position in an image using bilinear interpolation.

Parameters

image	The input image.
valR	The interpolated red color value.
valG	The interpolated green color value.
valB	The interpolated blue color value.
i	The vertical coordinate of the target position.
j	The horizontal coordinate of the target position.

Author: Norman Hutte

Date: 6 March 2024

◆ interpolate_color()

int obscurationPPM::interpolate_color	(	int	p11,
		int	p21,
		int	p12,
		int	p22,
		float	dx,
		float	dy )

static

Interpolates the color value of a pixel at a given position using bilinear interpolation.

Parameters

p11	The color value at the top-left corner of the interpolation rectangle.
p21	The color value at the top-right corner of the interpolation rectangle.
p12	The color value at the bottom-left corner of the interpolation rectangle.
p22	The color value at the bottom-right corner of the interpolation rectangle.
dx	The horizontal distance from the top-left corner of the interpolation rectangle to the target position.
dy	The vertical distance from the top-left corner of the interpolation rectangle to the target position.

Returns: The interpolated color value.

Author: Norman Hutte

Date: 6 March 2024

◆ newAverageBlurring()

void obscurationPPM::newAverageBlurring	(	ImageBase &	image,
		std::vector< ImageBase > &	o_images )

static

Applies new average blurring to an image using a given number of images.

Parameters

image	The input image.
o_images	The output images.

Author: Norman Hutte

Date: 6 March 2024

◆ RGB2GREY()

void obscurationPPM::RGB2GREY	(	ImageBase &	imColor,
		ImageBase &	imGrey )

static

Converts an RGB image to grayscale.

Parameters

imColor	The input RGB image.
imGrey	The output grayscale image.

Author: Norman Hutte

Date: 6 March 2024

◆ scrambling()

void obscurationPPM::scrambling	(	ImageBase &	image,
		ImageBase &	o_image,
		int	regionHeight,
		int	regionWidth )

static

Applies scrambling to an image using a given region size.

Parameters

image	The input image.
o_image	The output image.
regionHeight	The height of the scrambling region.
regionWidth	The width of the scrambling region.

Author: Norman Hutte

Date: 6 March 2024

◆ selectiveGroupEncryption()

void obscurationPPM::selectiveGroupEncryption	(	ImageBase &	image,
		ImageBase &	o_image,
		int	bitsGroup[8],
		int	groupSize )

static

Applies selective group encryption to an image using a given bit group and group size.

Parameters

image	The input image.
o_image	The output image.
bitsGroup	The bit group to encrypt.
groupSize	The size of the bit group.

Author: Norman Hutte

Date: 6 March 2024

◆ selectiveIndividualEncryption()

void obscurationPPM::selectiveIndividualEncryption	(	ImageBase &	image,
		ImageBase	o_images[8] )

static

Applies selective individual encryption to an image.

Parameters

image	The input image.
o_images	The output images.

Author: Norman Hutte

Date: 6 March 2024

◆ selectiveProgressiveEncryption()

void obscurationPPM::selectiveProgressiveEncryption	(	ImageBase &	image,
		ImageBase	o_images[8],
		bool	MSBtoLSB )

static

Applies selective progressive encryption to an image using a given encryption direction.

Parameters

image	The input image.
o_images	The output images.
MSBtoLSB	The encryption direction (true for MSB to LSB, false for LSB to MSB).

Author: Norman Hutte

Date: 6 March 2024

◆ writeDataOnTxt()

void obscurationPPM::writeDataOnTxt	(	std::vector< double > &	data,
		std::string	filename )

static

Writes data to a text file.

Parameters

data	The data to write.
filename	The name of the output file.

Author: Norman Hutte

Date: 6 March 2024

Static Public Member Functions

Detailed Description

Member Function Documentation

◆ areaAverager()

◆ areaScrambling()

◆ averageBlurring()

◆ averageByRegion()

◆ bilinearRedim299()

◆ compareImagesByHist()

◆ computeColorHist()

◆ computeImageMean()

◆ computePSNR()

◆ computePSNRforAllAlterations()

◆ computeSSIM()

◆ gaussianBlur()

◆ generateGaussianKernel()

◆ interpolate_bilinear()

◆ interpolate_color()

◆ newAverageBlurring()

◆ RGB2GREY()

◆ scrambling()

◆ selectiveGroupEncryption()

◆ selectiveIndividualEncryption()

◆ selectiveProgressiveEncryption()

◆ writeDataOnTxt()