Initial commit

apertures/All_3.txt

@@ -0,0 +1,4 @@
+3
+1	1	1
+1	1	1
+1	1	1

apertures/All_5.txt

@@ -0,0 +1,6 @@
+5
+1	1	1	1	1
+1	1	1	1	1
+1	1	1	1	1
+1	1	1	1	1
+1	1	1	1	1

apertures/Plus_3.txt

@@ -0,0 +1,4 @@
+3
+0	1	0
+1	1	1
+0	1	0

apertures/Plus_5.txt

@@ -0,0 +1,6 @@
+5
+0	0	1	0	0
+0	0	1	0	0
+1	1	1	1	1
+0	0	1	0	0
+0	0	1	0	0

kernels/Blur_11.txt

@@ -0,0 +1,13 @@
+11
+121
+1	1	1	1	1	1	1	1	1	1	1
+1	1	1	1	1	1	1	1	1	1	1
+1	1	1	1	1	1	1	1	1	1	1
+1	1	1	1	1	1	1	1	1	1	1
+1	1	1	1	1	1	1	1	1	1	1
+1	1	1	1	1	1	1	1	1	1	1
+1	1	1	1	1	1	1	1	1	1	1
+1	1	1	1	1	1	1	1	1	1	1
+1	1	1	1	1	1	1	1	1	1	1
+1	1	1	1	1	1	1	1	1	1	1
+1	1	1	1	1	1	1	1	1	1	1

kernels/Blur_3.txt

@@ -0,0 +1,5 @@
+3
+9
+1	1	1
+1	1	1
+1	1	1

kernels/East.txt

@@ -0,0 +1,5 @@
+3
+1
+-1	1	1
+-1	-2	1
+-1	1	1

kernels/Laplacian.txt

@@ -0,0 +1,5 @@
+3
+1
+0	-1	0
+-1	4	-1
+0	-1	0

kernels/Sharp.txt

@@ -0,0 +1,5 @@
+3
+4
+-1	-1	-1
+-1	12	-1
+-1	-1	-1

kernels/Sobel_h.txt

@@ -0,0 +1,5 @@
+3
+1
+-1 -2 -1
+ 0  0  0
+ 1  2  1

kernels/Sobel_v.txt

@@ -0,0 +1,5 @@
+3
+1
+-1 0 1
+-2 0 2
+-1 0 1

lab1_1/lab1_1.c

@@ -0,0 +1,49 @@
+#include <stdlib.h>
+#include <string.h>
+#include "png_wrapper.h"
+
+static void process_image(struct Image img, unsigned char threshold)
+{
+	for (size_t y = 0; y < img.height; y++)
+		for (size_t x = 0; x < img.width; x++)
+			img.pixels[y][x] = img.pixels[y][x] >= threshold ? 255 : 0;
+}
+
+int main(int argc, char * const argv[])
+{
+	if (argc < 3 || argc > 4)
+		error("usage: %s <input_file> [<output_file>] <threshold (0-255)>",
+			  argv[0]);
+
+	char *input_filename = argv[1];
+	char *output_filename;
+	char *s_threshold;
+
+	if (argc == 4)
+	{
+		output_filename = argv[2];
+		s_threshold = argv[3];
+	}
+	else
+	{
+		output_filename = alloca(strlen(input_filename) + sizeof("_out.png"));
+		strcpy(output_filename, input_filename);
+		strcat(output_filename, "_out.png");
+		s_threshold = argv[2];
+	}
+
+	int threshold = atoi(s_threshold);
+	if (threshold < 0 || threshold > 255)
+		error("wrong threshold (%d)", threshold);
+
+	struct Image img = read_grayscale_png(input_filename);
+	printf("Input file \"%s\" opened (width = %u, height = %u)\n",
+		   input_filename, img.width, img.height);
+
+	process_image(img, (unsigned char) threshold);
+
+	write_grayscale_png(img, output_filename);
+	free_pixels(img);
+
+	return 0;
+}

lab1_2/lab1_2.c

@@ -0,0 +1,64 @@
+#include <stdlib.h>
+#include <string.h>
+#include "png_wrapper.h"
+
+static inline void add_sat(struct Image img, int x, int y, double a)
+{
+	if (x < 0 || y < 0 || x >= img.width || y >= img.height)
+		return;
+
+	int sum = img.pixels[y][x] + a + 0.5;
+
+	if (sum < 0)
+		sum = 0;
+	else if (sum > 255)
+		sum = 255;
+
+	img.pixels[y][x] = sum;
+}
+
+static void process_image(struct Image img)
+{
+	for (int y = 0; y < img.height; y++)
+		for (int x = 0; x < img.width; x++)
+		{
+			unsigned char old_val = img.pixels[y][x];
+			unsigned char new_val = (old_val / 128) * 255;
+			img.pixels[y][x] = new_val;
+			int err = old_val - new_val;
+
+			add_sat(img, x + 1, y + 0, err * 7 / 16.0);
+			add_sat(img, x - 1, y + 1, err * 3 / 16.0);
+			add_sat(img, x + 0, y + 1, err * 5 / 16.0);
+			add_sat(img, x + 1, y + 1, err * 1 / 16.0);
+		}
+}
+
+int main(int argc, char * const argv[])
+{
+	if (argc < 2 || argc > 3)
+		error("usage: %s <input_file> [<output_file>]", argv[0]);
+
+	char *input_filename = argv[1];
+	char *output_filename;
+
+	if (argc == 3)
+		output_filename = argv[2];
+	else
+	{
+		output_filename = alloca(strlen(input_filename) + sizeof("_out.png"));
+		strcpy(output_filename, input_filename);
+		strcat(output_filename, "_out.png");
+	}
+
+	struct Image img = read_grayscale_png(input_filename);
+	printf("Input file \"%s\" opened (width = %u, height = %u)\n",
+		   input_filename, img.width, img.height);
+
+	process_image(img);
+
+	write_grayscale_png(img, output_filename);
+	free_pixels(img);
+
+	return 0;
+}

lab2_1/lab2_1.c

@@ -0,0 +1,60 @@
+#include <stdlib.h>
+#include <string.h>
+#include "png_wrapper.h"
+
+static void process_image(struct Image in, struct Image out, double N)
+{
+	for (size_t y = 0; y < out.height; y++)
+		for (size_t x = 0; x < out.width; x++)
+		{
+			size_t in_x = x / N + 0.5,
+				   in_y = y / N + 0.5;
+
+			if (in_x > in.width  - 1) in_x = in.width  - 1;
+			if (in_y > in.height - 1) in_y = in.height - 1;
+
+			out.pixels[y][x] = in.pixels[in_y][in_x];
+		}
+}
+
+int main(int argc, char * const argv[])
+{
+	if (argc < 3 || argc > 4)
+		error("usage: %s <input_file> [<output_file>] <N (0.0-10.0)>", argv[0]);
+
+	char *input_filename = argv[1];
+	char *output_filename;
+	char *sN;
+
+	if (argc == 4)
+	{
+		output_filename = argv[2];
+		sN = argv[3];
+	}
+	else
+	{
+		output_filename = alloca(strlen(input_filename) + sizeof("_out.png"));
+		strcpy(output_filename, input_filename);
+		strcat(output_filename, "_out.png");
+		sN = argv[2];
+	}
+
+	double N = atof(sN);
+	if (N <= 0.0 || N > 10.0)
+		error("N should be in the range 0.0-10.0");
+
+	struct Image in = read_grayscale_png(input_filename);
+	printf("Input file \"%s\" opened (width = %u, height = %u)\n",
+		   input_filename, in.width, in.height);
+
+	struct Image out = { in.width * N + 0.5, in.height * N + 0.5 };
+	alloc_pixels(&out);
+
+	process_image(in, out, N);
+	free_pixels(in);
+
+	write_grayscale_png(out, output_filename);
+	free_pixels(out);
+
+	return 0;
+}

lab2_2/lab2_2.c

@@ -0,0 +1,75 @@
+#include <stdlib.h>
+#include <string.h>
+#include "png_wrapper.h"
+
+static void process_image(struct Image in, struct Image out, double N)
+{
+	for (size_t y = 0; y < out.height; y++)
+		for (size_t x = 0; x < out.width; x++)
+		{
+			size_t in_x = x / N,
+				   in_y = y / N;
+
+			if (in_x > in.width  - 2) in_x = in.width  - 2;
+			if (in_y > in.height - 2) in_y = in.height - 2;
+
+			unsigned char I00 = in.pixels[in_y + 0][in_x + 0],
+						  I10 = in.pixels[in_y + 0][in_x + 1],
+						  I01 = in.pixels[in_y + 1][in_x + 0],
+						  I11 = in.pixels[in_y + 1][in_x + 1];
+
+			double u = x / N - in_x,
+				   v = y / N - in_y;
+
+			int res = I00 * (1-u) * (1-v)
+					+ I10 *    u  * (1-v)
+					+ I01 * (1-u) *    v
+					+ I11 *    u  *    v + 0.5;
+
+			if (res < 0) res = 0;
+			if (res > 255) res = 255;
+			out.pixels[y][x] = res;
+		}
+}
+
+int main(int argc, char * const argv[])
+{
+	if (argc < 3 || argc > 4)
+		error("usage: %s <input_file> [<output_file>] <N (0.0-10.0)>", argv[0]);
+
+	char *input_filename = argv[1];
+	char *output_filename;
+	char *sN;
+
+	if (argc == 4)
+	{
+		output_filename = argv[2];
+		sN = argv[3];
+	}
+	else
+	{
+		output_filename = alloca(strlen(input_filename) + sizeof("_out.png"));
+		strcpy(output_filename, input_filename);
+		strcat(output_filename, "_out.png");
+		sN = argv[2];
+	}
+
+	double N = atof(sN);
+	if (N <= 0.0 || N > 10.0)
+		error("N should be in the range 0.0-10.0");
+
+	struct Image in = read_grayscale_png(input_filename);
+	printf("Input file \"%s\" opened (width = %u, height = %u)\n",
+		   input_filename, in.width, in.height);
+
+	struct Image out = { in.width * N + 0.5, in.height * N + 0.5 };
+	alloc_pixels(&out);
+
+	process_image(in, out, N);
+	free_pixels(in);
+
+	write_grayscale_png(out, output_filename);
+	free_pixels(out);
+
+	return 0;
+}

lab3/lab3.c

@@ -0,0 +1,65 @@
+#include <stdlib.h>
+#include <string.h>
+#include "png_wrapper.h"
+
+static void process_images(struct Image top, struct Image bot,
+						   struct Image alpha, struct Image out)
+{
+	for (int y = 0; y < out.height; y++)
+		for (int x = 0; x < out.width; x++)
+		{
+			double a = alpha.pixels[y][x] / 255.0;
+
+			int res = top.pixels[y][x] * (1 - a)
+					+ bot.pixels[y][x] * a + 0.5;
+
+			if (res > 255) res = 255;
+			out.pixels[y][x] = res;
+		}
+}
+
+int main(int argc, char * const argv[])
+{
+	if (argc < 4 || argc > 5)
+		error("usage: %s <top_file> <bottom_file> "
+			  "<alpha_channel_file> [<output_file>]", argv[0]);
+
+	char *input1_filename = argv[1];
+	char *input2_filename = argv[2];
+	char *input3_filename = argv[3];
+	char *output_filename;
+
+	if (argc == 5)
+		output_filename = argv[4];
+	else
+	{
+		output_filename = alloca(strlen(input1_filename) + sizeof("_out.png"));
+		strcpy(output_filename, input1_filename);
+		strcat(output_filename, "_out.png");
+	}
+
+	struct Image in1 = read_grayscale_png(input1_filename);
+	printf("Top input file \"%s\" opened (width = %u, height = %u)\n",
+		   input1_filename, in1.width, in1.height);
+
+	struct Image in2 = read_grayscale_png(input2_filename);
+	printf("Bottom input file \"%s\" opened (width = %u, height = %u)\n",
+		   input2_filename, in2.width, in2.height);
+
+	struct Image in3 = read_grayscale_png(input3_filename);
+	printf("Alpha channel input file \"%s\" opened (width = %u, height = %u)\n",
+		   input3_filename, in3.width, in3.height);
+
+	struct Image out = { in1.width, in2.height };
+	alloc_pixels(&out);
+
+	process_images(in1, in2, in3, out);
+	free_pixels(in1);
+	free_pixels(in2);
+	free_pixels(in3);
+
+	write_grayscale_png(out, output_filename);
+	free_pixels(out);
+
+	return 0;
+}