Add src

src/preview_mnist.c

@@ -0,0 +1,61 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <inttypes.h>
+
+
+void print_image(unsigned int width, unsigned int height, FILE* ptr, int start) {
+    unsigned char buffer[width*height+start];
+
+    fread(buffer, sizeof(buffer), 1, ptr);
+
+    int cur;
+
+    for (int i=0; i<height; i++) {
+        for (int j=0; j<width; j++) {
+            cur = buffer[start+j+i*width];
+            if (cur > 150)
+                printf("0");
+            else {
+                if (cur > 100)
+                    printf(".");
+                else
+                    printf(" ");
+            }
+        }
+        printf("\n");
+    }
+    printf("\t\t---\n");
+}
+
+
+
+void print_bytes(char* filename) {
+    unsigned char buffer[4];
+    FILE *ptr;
+    
+    ptr = fopen(filename, "rb");
+
+    fread(buffer, sizeof(buffer), 1, ptr);
+
+    uint32_t magic_number = buffer[0];
+    uint32_t number_of_images = (int)buffer[1];
+    unsigned int height = buffer[2];
+    unsigned int width = buffer[3];
+
+
+    printf("magic number: %" PRIu32 "\n", magic_number);
+    printf("number of images: %" PRIu32 "\n", number_of_images);
+    printf("%x x %x\n\n", width, height);
+    for (int i=0; i < number_of_images; i++)
+        print_image(width, height, ptr, (i*width*height)+4);
+}
+
+int main(int argc, char *argv[]) {
+    if (argc == 1) {
+        printf("Utilisation: %s [FILE]\n", argv[0]);
+        return 1;
+    }
+    print_bytes(argv[1]);
+    return 0;
+}