imageInput: Zwischenstand

imageInput.c

@@ -1,4 +1,4 @@
-##include <stdio.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include "imageInput.h"
@@ -6,20 +6,22 @@
 #define BUFFER_SIZE 100
 #define FILE_HEADER_STRING "__info2_image_file_format__"
 
-
 /*
- * Hilfsfunktionen 
+ * Diese Hilfsfunktionen kümmern sich um:
+ * - Das Öffnen der Datei und Überprüfen des Dateinamens
+ * - Das Überprüfen des Headers, um sicherzustellen, dass es sich um die richtige Datei handelt
+ * - Das Einlesen der Metadaten (Anzahl der Bilder, Bildbreite und -höhe)
+ *  -> Die Hilfsfunktionen garantieren, dass die Datei gültig ist, bevor mit dem Einlesen der Bilddaten fortgefahren wird.
  */
  
-
 static FILE *openImageFile(const char *path) // Checks if the given filename pointer is valid (not NULL).
 {  
-if (path == NULL)
+    if (path == NULL)
     {
         return NULL;
     }
 
-    return fopen(path, "rb");  //opening document in binear 
+    return fopen(path, "rb");  // opening document in binary mode
 }
 
 static int readAndCheckHeader(FILE *file) // gets the length of the header text
@@ -27,20 +29,19 @@ static int readAndCheckHeader(FILE *file) // gets the length of the header text
     size_t headerLength = strlen(FILE_HEADER_STRING);
     char buffer[BUFFER_SIZE];
 
-    if (headerLength + 1 > BUFFER_SIZE) //checks if buffer is big enough for header size
+    if (headerLength + 1 > BUFFER_SIZE) // checks if buffer is big enough for header size
     {
         return 0;
     }
 
     if (fread(buffer, 1, headerLength, file) != headerLength) // Checks if reading the expected number of header bytes from the file succeeded
-
+    {
         return 0;
-    
+    }
 
     buffer[headerLength] = '\0'; // add string terminator so the header becomes a valid C-string
 
     if (strcmp(buffer, FILE_HEADER_STRING) != 0) // checks if the expected header matches the header read from the file
-
     {
         return 0;
     }
@@ -48,25 +49,81 @@ static int readAndCheckHeader(FILE *file) // gets the length of the header text
     return 1; /* Header ok */
 }
 
-
-
-
 static int readImageMetaData(FILE *file, // reads the metadata (count, width, height) from the file and stores them in the provided pointers
                              unsigned short *count,
                              unsigned short *width,
                              unsigned short *height)
 {
+    if (fread(count, sizeof(unsigned short), 1, file) != 1) // read the number of images from the file
+    {    
+        return 0;
+    }
+    if (fread(width, sizeof(unsigned short), 1, file) != 1) // reads the image width
+    {
+        return 0;
+    }
+    if (fread(height, sizeof(unsigned short), 1, file) != 1) // reads the image height
+    {
+        return 0;
+    }
 
+    if (*count == 0 || *width == 0 || *height == 0) // check for invalid metadata (count, width or height cannot be zero)
+    {
+        return 0;
+    }
 
+    return 1;
+}
 
+GrayScaleImageSeries *readImages(const char *path)
+{
+    // 1. Open the file
+    FILE *file = openImageFile(path);
+    if (file == NULL) {
+        return NULL;
+    }
 
+    // 2. Check the header
+    if (!readAndCheckHeader(file)) {
+        return NULL;
+    }
 
+    // 3. Read image metadata
+    unsigned short count, width, height;
+    if (!readImageMetaData(file, &count, &width, &height)) {
+        return NULL;
+    }
 
-    /*
-    Hauptfunktion
-    */
+    // 4. Allocate memory for image series
+    GrayScaleImageSeries *series = malloc(sizeof(GrayScaleImageSeries)); // Allocate memory for the image series, images, and labels. Return NULL if allocation fails.
 
+    if (series == NULL) {
+        return NULL;
+    }
+    series->count = count;
+    series->images = calloc(count, sizeof(GrayScaleImage));
+    series->labels = malloc(count * sizeof(unsigned char));
+    if (series->images == NULL || series->labels == NULL) {
+        free(series);
+        return NULL;
+    }
 
+    // 5. Read the images and labels 
+    for (unsigned int i = 0; i < count; i++)
+    {
+        GrayScaleImage *image = &series->images[i];
+        unsigned char *label = &series->labels[i];
 
+        if (fread(image->buffer, sizeof(GrayScalePixelType), width * height, file) != width * height) // Check if the correct number of pixel values (width * height) were read for the image
+        {
+            return 0;
+        }
 
+        if (fread(label, sizeof(unsigned char), 1, file) != 1) // Check if the label for the image was successfully read (1 byte)
+        {
+            return 0;
+        }
+    }
    
+    return series;
+}