2 files changed, 113 insertions, 6 deletions

diff --git a/src/main.c b/src/main.c
index 242e464..0182328 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,16 +1,123 @@
 #include <stdio.h>
 #include <stdlib.h>
+#include <stdint.h>
 
 #include "ppm.h"
 
+static Image image_convolution(Image input, float kernel[9]);
+static void split_rgb(Image input, uint8_t *r, uint8_t *g, uint8_t *b);
+static void merge_rgb(Image *out, uint8_t *r, uint8_t *g, uint8_t *b);
+static uint8_t kernel_op(uint8_t *data, float kernel[9], int i, int j, int w, int h);
+
+Image
+image_convolution(Image input, float kernel[9])
+{
+    Image out;
+    out.width = input.width;
+    out.height = input.height;
+    out.pixel_bits = input.pixel_bits;
+
+    size_t n_pixels = out.width * out.height * 3;
+
+    out.data = calloc(n_pixels, sizeof(uint8_t));
+
+    if (out.data == NULL) {
+        perror("image_convolution() Error");
+        exit(1);
+    }
+
+    uint8_t *r, *g, *b;
+    r = calloc(input.width * input.height, sizeof(uint8_t));
+    g = calloc(input.width * input.height, sizeof(uint8_t));
+    b = calloc(input.width * input.height, sizeof(uint8_t));
+    split_rgb(input, r, g, b);
+
+    int i, j, index;
+    for (i = 0; i < input.height; i++) {
+        for (j = 0; j < input.width; j++) {
+            index = i * input.width + j;
+            r[index] = kernel_op(r, kernel, i, j, input.width, input.height);
+            g[index] = kernel_op(g, kernel, i, j, input.width, input.height);
+            b[index] = kernel_op(b, kernel, i, j, input.width, input.height);
+        }
+    }
+
+    merge_rgb(&out, r, g, b);
+    free(r);
+    free(g);
+    free(b);
+    return out;
+}
+
+void
+merge_rgb(Image *out, uint8_t *r, uint8_t *g, uint8_t *b)
+{
+    int i;
+    for (i = 0; i < out->width * out->height; i++) {
+        out->data[3 * i] = r[i];
+        out->data[3 * i + 1] = g[i];
+        out->data[3 * i + 2] = b[i];
+    }
+}
+
+uint8_t
+kernel_op(uint8_t *data, float kernel[9], int i, int j, int w, int h)
+{
+    float kernel_value = 0;
+    int ki, kj, img_index, index_i, index_j, index_k;
+    for (ki = 0; ki < 3; ki++) {
+        for (kj = 0; kj < 3; kj++) {
+            index_i = i + ki - 1; //height
+            index_j = j + kj - 1; //width
+            index_k = 3 * ki + kj;
+
+            if (index_i < 0
+                || index_i >= h
+                || index_j < 0
+                || index_j >= w)
+                kernel_value += data[i * w + j] * kernel[index_k];
+            else {
+                img_index = index_i * w + index_j;
+                kernel_value += data[img_index] * kernel[index_k];
+            }
+
+            kernel_value = (kernel_value > 255) ? 255: kernel_value;
+            kernel_value = (kernel_value < 0) ? 0: kernel_value;
+        }
+    }
+    return (uint8_t)kernel_value;
+}
+
+void
+split_rgb(Image input, uint8_t *r, uint8_t *g, uint8_t *b)
+{
+
+    if (!r || !g || !b) {
+        perror("rgb_split() Error");
+        exit(1);
+    }
+
+    int i; 
+    for (i = 0; i < input.width * input.height; i++) {
+        r[i] = input.data[3 * i];
+        g[i] = input.data[3 * i + 1];
+        b[i] = input.data[3 * i + 2];
+    }
+
+}
+
 int main(int argc, char *argv[])
 {
     Image img;
-    ppm_read("images/boxes_1.ppm", &img);
+    float kernel[9] = {
+        -1, -1, -1,
+        -1,  8, -1,
+        -1, -1, -1,
+    };
 
-    printf("width: %d\n", img.width);
-    printf("height: %d\n", img.height);
-    printf("bits: %d\n", img.pixel_bits);
-    printf("data[2]: %d\n", img.data[2]);
+    //for (int i = 0;  i < 9; i++) kernel[i] /= 16;
+    ppm_read("images/synth_1.ppm", &img);
+    Image out_img = image_convolution(img, kernel);
+    ppm_write("out.ppm", &out_img);
     return 0;
 }
diff --git a/src/ppm.c b/src/ppm.c
index f96e950..aded7cd 100644
--- a/src/ppm.c
+++ b/src/ppm.c
@@ -13,7 +13,7 @@ ppm_write(const char *file, Image *img)
         exit(1);
     }
 
-    size_t n_pixels;
+    size_t n_pixels = img->width * img->height * 3;
 
     fprintf(fp, "P6\n%d %d\n%d\n", img->width, img->height, img->pixel_bits);
     fwrite(img->data, n_pixels, sizeof(uint8_t), fp);