purecv

purecv is a single-header-style C library for classical computer vision operations.

Implementation pattern:

#define PCV_GET_FILTERS
#include "pcv_get_filters.h"

Note:

• The current codebase is primarily grayscale-oriented.

Current API

pcv_get_filters.h

• Define before include: PCV_GET_FILTERS
• Public function: int pcv_get_filters(int n, float *output, char *filter)
• What it does: Generates an n x n filter kernel into output.
• Supported filter names: BOX, SOBEL_X, SOBEL_Y, GAUSSIAN_BLUR

pcv_convolution.h

• Define before include: PCV_CONVOLUTION
• Public function: int pcv_convolve_U8(const unsigned char *input, int width, int height, const float *kernel, int k_width, int k_height, int stride, unsigned char *output, int padding)
• What it does: Convolves a grayscale unsigned char image and writes clamped unsigned char output.

pcv_convolution.h

• Define before include: PCV_CONVOLUTION
• Public function: int pcv_convolve_F(const unsigned char *input, int width, int height, const float *kernel, int k_width, int k_height, int stride, float *output, int padding)
• What it does: Convolves a grayscale unsigned char image and writes floating-point output.

pcv_convert_gray.h

• Define before include: PCV_CONVERT_GRAY
• Public function: int pcv_convert_gray(unsigned char *input, int width, int height, unsigned char *output)
• What it does: Converts a flat RGBRGB... byte array into a grayscale image.

pcv_floodfill.h

• Define before include: PCV_FLOODFILL
• Public function: int pcv_floodfill(const unsigned char *input, int width, int height, unsigned char *output, int (*seeds)[2], int num_seeds, int threshold, unsigned char new_val)
• What it does: Performs flood fill on a grayscale image using seed points in (y, x) order.

pcv_srm.h

• Define before include: PCV_SRM_IMPLEMENT
• Public function: int pcv_srm_segment(const unsigned char *original_data, int width, int height, int q, unsigned char *output)
• What it does: Runs Statistical Region Merging (SRM) segmentation and writes a boundary-marked output image.

pcv_normalize.h

• Define before include: PCV_NORMALIZE
• Public function: int pcv_general_norm(void *input, int height, int width, int bottom, int upp, int input_type)
• What it does: Normalizes the input image in place to the range [bottom, upp].
• Current input type convention: input_type == 1 means the buffer is treated as float. Any other value means the buffer is treated as unsigned char.
• Current behavior note: The function mutates the input buffer directly instead of writing to a separate output buffer.

Build / Usage Notes

pcv_convert_gray.h

• Expects a flat RGB byte layout: RGBRGBRGB...

pcv_floodfill.h

• Seed points are expected in (y, x) order.
• Current implementation supports 4-way flood fill.

pcv_normalize.h

• Assumes IEEE 754 floating-point layout.