Task1 sequential

.clang-format

@@ -0,0 +1,7 @@
+BasedOnStyle: LLVM
+UseTab: Always
+TabWidth: 4
+IndentWidth: 4
+ColumnLimit: 100
+AllowShortIfStatementsOnASingleLine: true
+AllowShortLoopsOnASingleLine: true

.clang-tidy

@@ -0,0 +1,12 @@
+Checks: >
+  clang-diagnostic-*,
+  clang-analyzer-*,
+  bugprone-*,
+  -bugprone-easily-swappable-parameters,
+  performance-*,
+  readability-*,
+  -readability-magic-numbers,
+  -readability-function-cognitive-complexity,
+  -readability-identifier-length,
+  -readability-braces-around-statements
+HeaderFilterRegex: '^(src|include)/.*'

.github/workflows/ci.yml

@@ -0,0 +1,36 @@
+name: C CI
+
+on:
+  push:
+  pull_request:
+    branches: [ "main" ]
+
+jobs:
+  build-and-test:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Install dependencies
+      run: |
+        sudo apt-get update
+        sudo apt-get install -y build-essential clang libcmocka-dev
+        sudo apt-get install -y build-essential clang clang-format clang-tidy libcmocka-dev bear
+
+    - name: Build
+      run: make CC=gcc
+
+    - name: Run tests
+      run: make test
+
+    - name: Check code formatting
+      run: |
+        find src/ -name '*.c' -o -name '*.h' | xargs clang-format --dry-run -Werror
+
+    - name: Generate compile_commands.json
+      run: bear -- make
+
+    - name: Static analysis
+      run: |
+        find src/ -name '*.c' | xargs clang-tidy --quiet

Makefile

@@ -0,0 +1,33 @@
+CC = gcc
+CFLAGS = -std=c11 -Wall -Wextra -O2 -D_POSIX_C_SOURCE=199309L \
+-Iinclude -Ithird_party/stb
+LDFLAGS = -lm
+TARGET = conv
+VPATH = src src/lib
+SRCS = main.c conv.c cli.c filters.c
+
+OBJS = $(SRCS:.c=.o)
+
+LIB_OBJS = conv.o cli.o filters.o
+TEST_SRC = tests/test_conv.c
+TEST_BIN = test_runner
+
+all: $(TARGET)
+
+$(TARGET): $(OBJS)
+	$(CC) $(CFLAGS) $^ -o $@ $(LDFLAGS)
+
+%.o: %.c
+	$(CC) $(CFLAGS) -c $< -o $@
+
+test: $(TEST_BIN)
+	./$(TEST_BIN)
+
+$(TEST_BIN): $(LIB_OBJS) $(TEST_SRC)
+	$(CC) -std=c11 -Wall -Wextra -O0 -g -Iinclude -Ithird_party/stb \
+	      $^ -o $@ -lm -lcmocka
+
+clean:
+	rm -f $(TARGET) $(OBJS) $(TEST_BIN)
+
+.PHONY: all test clean

README.md

@@ -0,0 +1,39 @@
+# Image Convolution — Task 1: Sequential
+
+Simple CLI tool for applying convolution filters images.
+
+## Build & Run
+
+```bash
+make                    # build
+./conv in.bmp out.bmp --filter sharpen   # apply filter
+make test               # run tests
+```
+
+## Usage
+
+```bash
+./conv <input> <output> --filter <name> [--repeat=N]
+```
+
+**Filters**: identity, blur, gaussian, sharpen, edges, emboss
+
+**Formats**: BMP, PNG, JPEG
+
+## Example
+
+```bash
+./conv photo.jpg result.png --filter edges
+```
+
+## Performance (sequential, white_cat.jpeg, avg over ×100 runs)
+
+| Filter   | Kernel | Time (ms) |
+| -------- | ------ | --------- |
+| sharpen  | 3×3    | 30.7      |
+| sharpen5 | 5×5    | 75.9      |
+| sharpen7 | 7×7    | 144.6     |
+| sharpen9 | 9×9    | 235.6     |
+
+Runtime scales roughly as kernel area (k²): 3×3→9×9 gives ~7.7× slowdown vs theoretical 9×.
+Single runs show up to 30% variance; repeated runs stabilize within ~2%

include/cli.h

@@ -0,0 +1,11 @@
+#pragma once
+#include "conv.h"
+
+typedef struct {
+	const char *input_path;
+	const char *output_path;
+	const char *filter_name;
+} CliConfig;
+
+int cli_parse(int argc, char *argv[], CliConfig *cfg);
+void cli_print_help(const char *prog_name);

include/conv.h

@@ -0,0 +1,14 @@
+#pragma once
+
+#include "filters.h"
+#include <stddef.h>
+#include <stdint.h>
+
+typedef struct {
+	uint8_t *pixels;
+	size_t width;
+	size_t height;
+	int channels;
+} Image;
+
+void convolve_sequential(const Image *input, Image *output, const struct Filter *filter);

include/filters.h

@@ -0,0 +1,47 @@
+#pragma once
+
+#include <stddef.h>
+
+struct Filter {
+	size_t size;
+	double *data;
+	double factor;
+	double bias;
+};
+
+/* 3x3 filters */
+struct Filter filter_identity(void);
+struct Filter filter_blur(void);
+struct Filter filter_gaussian(void);
+struct Filter filter_sharpen(void);
+struct Filter filter_edges(void);
+struct Filter filter_emboss(void);
+
+/* 5x5 filters */
+struct Filter filter_blur5(void);
+struct Filter filter_gaussian5(void);
+struct Filter filter_sharpen5(void);
+struct Filter filter_edges5(void);
+struct Filter filter_emboss5(void);
+
+/* 7x7 filters */
+struct Filter filter_blur7(void);
+struct Filter filter_gaussian7(void);
+struct Filter filter_sharpen7(void);
+struct Filter filter_edges7(void);
+struct Filter filter_emboss7(void);
+
+/* 9x9 filters */
+struct Filter filter_blur9(void);
+struct Filter filter_gaussian9(void);
+struct Filter filter_sharpen9(void);
+struct Filter filter_edges9(void);
+struct Filter filter_emboss9(void);
+
+typedef struct {
+	const char *name;
+	struct Filter (*create)(void);
+} FilterDef;
+
+extern const FilterDef filter_list[];
+extern const size_t filter_count;

src/lib/cli.c

@@ -0,0 +1,57 @@
+#include "cli.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+void cli_print_help(const char *prog) {
+	printf("Usage: %s <input> <output> --filter <name>\n"
+		   "Arguments:\n"
+		   "  input    Input image (BMP/PNG/JPG)\n"
+		   "  output   Output image (BMP/PNG/JPG)\n"
+		   "Options:\n"
+		   "  --filter <name>   Filter: identity, blur, gaussian, sharpen, edges, emboss\n"
+		   "Add suffix 5/7/9 for larger kernels (e.g., emboss9)\n"
+		   "  -h, --help        Show this help\n"
+		   "Example:\n"
+		   "  %s photo.bmp out.bmp --filter edges5 \n",
+		   prog, prog);
+}
+
+int cli_parse(int argc, char *argv[], CliConfig *cfg) {
+	cfg->input_path = NULL;
+	cfg->output_path = NULL;
+	cfg->filter_name = NULL;
+	int pos = 0;
+
+	for (int i = 1; i < argc; ++i) {
+		if (strcmp(argv[i], "-h") == 0 || strcmp(argv[i], "--help") == 0) {
+			cli_print_help(argv[0]);
+			return 0;
+		}
+		if (strcmp(argv[i], "--filter") == 0) {
+			if (++i < argc)
+				cfg->filter_name = argv[i];
+			else {
+				fprintf(stderr, "Error: --filter requires a value\n");
+				return 0;
+			}
+			continue;
+		}
+		if (pos == 0)
+			cfg->input_path = argv[i];
+		else if (pos == 1)
+			cfg->output_path = argv[i];
+		else {
+			fprintf(stderr, "Error: too many positional arguments\n");
+			return 0;
+		}
+		pos++;
+	}
+
+	if (!cfg->input_path || !cfg->output_path || !cfg->filter_name) {
+		fprintf(stderr, "Error: missing required arguments\n");
+		cli_print_help(argv[0]);
+		return 0;
+	}
+	return 1;
+}

src/lib/conv.c

@@ -0,0 +1,44 @@
+#include "conv.h"
+#include <stddef.h>
+#include <stdint.h>
+
+#define PIXEL_MIN 0
+#define PIXEL_MAX 255
+#define ROUNDING_OFFSET 0.5
+
+void convolve_sequential(const Image *input, Image *output, const struct Filter *filter) {
+	const int radius = (int)(filter->size / 2);
+	const double factor = filter->factor;
+	const double bias = filter->bias;
+	const double *kernel = filter->data;
+
+	const size_t width = input->width;
+	const size_t height = input->height;
+	const int channels = input->channels;
+	const size_t stride = width * channels;
+
+	for (size_t y = 0; y < height; ++y) {
+		for (size_t x = 0; x < width; ++x) {
+			for (int c = 0; c < channels; ++c) {
+				double acc = 0.0;
+				for (int fy = 0; fy < (int)filter->size; ++fy) {
+					for (int fx = 0; fx < (int)filter->size; ++fx) {
+						int sy = (int)y + fy - radius;
+						int sx = (int)x + fx - radius;
+						sy %= (int)height;
+						if (sy < 0) sy += (int)height;
+						sx %= (int)width;
+						if (sx < 0) sx += (int)width;
+						double pixel =
+							input->pixels[(size_t)sy * stride + (size_t)sx * channels + (size_t)c];
+						acc += kernel[fy * filter->size + fx] * pixel;
+					}
+				}
+				double value = acc * factor + bias;
+				if (value < PIXEL_MIN) value = PIXEL_MIN;
+				if (value > PIXEL_MAX) value = PIXEL_MAX;
+				output->pixels[y * stride + x * channels + c] = (uint8_t)(value + ROUNDING_OFFSET);
+			}
+		}
+	}
+}