Core image processing functions for img2num project. More...

#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>

Include dependency graph for cimg2num.h:

This graph shows which files directly or indirectly include this file:

Functions
void	img2num_gaussian_blur_fft (uint8_t *image, size_t width, size_t height, double sigma)
	Apply a Gaussian blur to an image using FFT. More...

void	img2num_invert_image (uint8_t *ptr, int width, int height)
	Invert the pixel values of an image. More...

void	img2num_threshold_image (uint8_t *ptr, const int width, const int height, const int num_thresholds)
	Apply a thresholding operation to an image. More...

void	img2num_black_threshold_image (uint8_t *ptr, const int width, const int height, const int num_thresholds)
	Apply black-thresholding to an image. More...

void	img2num_kmeans (const uint8_t data, uint8_t out_data, int32_t *out_labels, const int32_t width, const int32_t height, const int32_t k, const int32_t max_iter, const uint8_t color_space)
	Perform k-means clustering on image data. More...

void	img2num_bilateral_filter (uint8_t *image, size_t width, size_t height, double sigma_spatial, double sigma_range, uint8_t color_space)
	Apply bilateral filtering to an image. More...

char *	img2num_labels_to_svg (uint8_t data, int32_t labels, const int width, const int height, const int min_area, const bool draw_contour_borders)
	Convert labeled regions of an image into an SVG string. More...

Detailed Description

Core image processing functions for img2num project.

This file declares functions for image manipulation, clustering, filtering, and conversion to SVG. Functions operate on raw image buffers (uint8_t*).

Definition in file cimg2num.h.

Function Documentation

◆ img2num_bilateral_filter()

void img2num_bilateral_filter	(	uint8_t *	image,
		size_t	width,
		size_t	height,
		double	sigma_spatial,
		double	sigma_range,
		uint8_t	color_space
	)

Apply bilateral filtering to an image.

Parameters

image	Pointer to RGBA pixel buffer.
width	Width of the image in pixels.
height	Height of the image in pixels.
sigma_spatial	Standard deviation for spatial Gaussian (proximity weight).
sigma_range	Standard deviation for range Gaussian (intensity similarity weight).
color_space	Color space flag (0 = CIE LAB, 1 = RGB).

Note: The filter modifies the image buffer in-place.; Dox File: doxygen/img2num.h.dox

Definition at line 35 of file cimg2num.cpp.

                                                                        {
     img2num::clear_last_error_and_catch(img2num::bilateral_filter, image, width, height,
                                         sigma_spatial, sigma_range, color_space);
 }

◆ img2num_black_threshold_image()

void img2num_black_threshold_image	(	uint8_t *	ptr,
		const int	width,
		const int	height,
		const int	num_thresholds
	)

Apply black-thresholding to an image.

Parameters

ptr	Pointer to the image buffer.
width	Width of the image in pixels.
height	Height of the image in pixels.
num_thresholds	Number of thresholds to apply.

Note: Similar to threshold_image but prioritizes darker pixels.; Dox File: doxygen/img2num.h.dox

Definition at line 22 of file cimg2num.cpp.

                                                              {
     img2num::clear_last_error_and_catch(img2num::black_threshold_image, ptr, width, height,
                                         num_thresholds);
 }

◆ img2num_gaussian_blur_fft()

void img2num_gaussian_blur_fft	(	uint8_t *	image,
		size_t	width,
		size_t	height,
		double	sigma
	)

Apply a Gaussian blur to an image using FFT.

Parameters

image	Pointer to the image buffer (RGBA).
width	Width of the image in pixels.
height	Height of the image in pixels.
sigma	Standard deviation for Gaussian kernel.

Note: The operation modifies the image buffer in-place.; Dox File: doxygen/img2num.h.dox

Definition at line 8 of file cimg2num.cpp.

                                                                                           {
     img2num::clear_last_error_and_catch(img2num::gaussian_blur_fft, image, width, height, sigma);
 }

◆ img2num_invert_image()

void img2num_invert_image	(	uint8_t *	ptr,
		int	width,
		int	height
	)

Invert the pixel values of an image.

Parameters

ptr	Pointer to the image buffer.
width	Width of the image in pixels.
height	Height of the image in pixels.

Note: Each pixel value is replaced by 255 - original_value.; Dox File: doxygen/img2num.h.dox

Definition at line 12 of file cimg2num.cpp.

                                                                  {
     img2num::clear_last_error_and_catch(img2num::invert_image, image, width, height);
 }

◆ img2num_kmeans()

void img2num_kmeans	(	const uint8_t *	data,
		uint8_t *	out_data,
		int32_t *	out_labels,
		const int32_t	width,
		const int32_t	height,
		const int32_t	k,
		const int32_t	max_iter,
		const uint8_t	color_space
	)

Perform k-means clustering on image data.

Parameters

data	Pointer to input image data buffer.
out_data	Pointer to output buffer where clustered pixel values are stored.
out_labels	Pointer to output buffer for cluster labels per pixel.
width	Width of the image in pixels.
height	Height of the image in pixels.
k	Number of clusters to compute.
max_iter	Maximum number of iterations for the algorithm.
color_space	Color space flag (0 = CIE LAB, 1 = RGB).

Note: The function does not modify the input buffer.; Dox File: doxygen/img2num.h.dox

Definition at line 28 of file cimg2num.cpp.

                                                                        {
     img2num::clear_last_error_and_catch(img2num::kmeans, data, out_data, out_labels, width, height,
                                         k, max_iter, color_space);
 }

◆ img2num_labels_to_svg()

char* img2num_labels_to_svg	(	uint8_t *	data,
		int32_t *	labels,
		const int	width,
		const int	height,
		const int	min_area,
		const bool	draw_contour_borders
	)

Convert labeled regions of an image into an SVG string.

Parameters

data	Pointer to image data buffer.
labels	Pointer to label buffer, indicating region for each pixel.
width	Width of the image in pixels.
height	Height of the image in pixels.
min_area	Minimum area (in pixels) for a region to be included in the SVG.
draw_contour_borders	If true, contours of labeled regions will be drawn.

Returns: Pointer to a dynamically allocated C-string containing the SVG data.

Note: Caller is responsible for freeing the returned string.; Dox File: doxygen/img2num.h.dox

Definition at line 41 of file cimg2num.cpp.

                                                                                  {
     char *result{nullptr};
     img2num::clear_last_error_and_catch(
         [&](uint8_t *d, int32_t *l, int w, int h, int min_a, bool draw_contours) {
             result = img2num::labels_to_svg(d, l, w, h, min_a, draw_contours);
         },
         data, labels, width, height, min_area, draw_contour_borders);
     return result;
 }

◆ img2num_threshold_image()

void img2num_threshold_image	(	uint8_t *	ptr,
		const int	width,
		const int	height,
		const int	num_thresholds
	)

Apply a thresholding operation to an image.

Parameters

ptr	Pointer to the image buffer.
width	Width of the image in pixels.
height	Height of the image in pixels.
num_thresholds	Number of thresholds to apply.

Note: Thresholds split pixel intensity ranges into discrete levels.; Dox File: doxygen/img2num.h.dox

Definition at line 16 of file cimg2num.cpp.

                                                        {
     img2num::clear_last_error_and_catch(img2num::threshold_image, ptr, width, height,
                                         num_thresholds);
 }