Funktion aufgeteilt

imageInput.c

@@ -5,18 +5,204 @@
 
 #define BUFFER_SIZE 100
 #define FILE_HEADER_STRING "__info2_image_file_format__"
+#define HEADER_LEN (sizeof(FILE_HEADER_STRING) - 1) //-1, um \0 Character rauszufiltern
 
 // TODO Implementieren Sie geeignete Hilfsfunktionen für das Lesen der Bildserie aus einer Datei
 
+static int checkDimensions(unsigned int width, unsigned int height){
+
+    int ok = 0;
+    
+    if(width > 0 && height > 0)
+        return ok = 1;
+    
+    else 
+        return ok = 0;
+
+}
+
+static int checkHeader(const GrayScalePixelType *buffer){
+
+    int ok = 0;
+    char header[HEADER_LEN + 1]; //Array mit Platz für Header Länge + \0 Character -> String
+
+    // Jeder Byte in String kopieren
+    for(int i = 0; i < HEADER_LEN; i++){
+
+        header[i] = buffer[i];
+
+    }
+
+    header[HEADER_LEN] = '\0'; // Nullterminator am Ende anhängen
+
+    if(strcmp(header, FILE_HEADER_STRING) == 0) // wenn beide identische sind gibt cmp 0 zurück
+        return ok = 1;
+
+    else
+        return ok = 0;
+
+}
+
+static FILE *openImageFile(const char *path)
+{
+    return fopen(path, "rb");
+}
+
+static int readHeaderFromFile(FILE *fp, GrayScalePixelType *headerBuffer)
+{
+    if (fread(headerBuffer, sizeof(GrayScalePixelType),HEADER_LEN, fp) != HEADER_LEN)
+    {
+        return 0;
+    }
+    return 1;
+}
+
+static int readMetaData(FILE *fp, unsigned int *numImages, unsigned int *width, unsigned int *height)
+{
+    if (fread(numImages, sizeof(unsigned int), 1, fp) != 1 || fread(width, sizeof(unsigned int), 1, fp) != 1 || fread(height, sizeof(unsigned int), 1, fp) != 1)
+
+    {
+    return 0;
+    }
+    return 1;
+}
+
+static GrayScaleImageSeries *allocateSeriesStruct(void)
+{
+    GrayScaleImageSeries *series = malloc(sizeof(GrayScaleImageSeries));
+    return series;
+}
+
+static int allocateImageAndLabelArrays(GrayScaleImageSeries *series, unsigned int numImages, FILE *fp)
+{
+    series->count = numImages;
+    //Speicher für die Pointer an sich belegen
+    series->images = malloc(numImages * sizeof(GrayScaleImage));
+    series->labels = malloc(numImages * sizeof(unsigned char));
+
+    if (!series->images || !series->labels)
+    {
+        free(series->images); //wenn trotzdem was reingeschrieben wurde, dann freigeben
+        free(series->labels);
+        free(series);
+
+        fclose(fp);
+        return 0;
+    }
+
+    return 1;
+}
+
+static int allocateBufferForImages(GrayScaleImageSeries *series, unsigned int numImages, unsigned int width, unsigned int height, FILE *fp)
+{
+    for (unsigned int i = 0; i < numImages; i++)
+    {
+        series ->images[i].buffer = malloc(width * height);
+        if (series ->images[i].buffer == NULL) 
+        {
+            for (unsigned int j = 0; j < i; j++)
+            {
+                free(series->images[j].buffer);
+            }
+
+            free(series->images);
+            free(series->labels);
+            free(series);
+
+            fclose(fp);
+            return 0;
+        }
+    }
+    return 1;
+}
+
+static int readImagesAndLabels(FILE *fp, GrayScaleImageSeries *series, unsigned int numImages, unsigned int width, unsigned int height)
+{
+    for (unsigned int i = 0; i < numImages; i++)
+    {
+        series->images[i].width = width;
+        series->images[i].height = height;
+
+        if (fread(series->images[i].buffer, 1, width *height, fp) != (width * height))
+        {
+            clearSeries(series);
+            fclose(fp);
+            return 0;
+        }
+
+        fread(&series->labels[i], 1, 1, fp);
+    }
+
+    return 1;
+}
+
+
 // TODO Vervollständigen Sie die Funktion readImages unter Benutzung Ihrer Hilfsfunktionen
 GrayScaleImageSeries *readImages(const char *path)
 {
     GrayScaleImageSeries *series = NULL;
 
-    return series;
+    FILE *fp = openImageFile(path);
+    if (!fp)
+    return NULL;
+
+    GrayScalePixelType header[HEADER_LEN];
+
+    if (!readHeaderFromFile(fp, header))
+    {
+        fclose(fp);
+        return NULL;
     }
 
+    if (!checkHeader(header))
+    {
+        fclose(fp);
+        return NULL;
+    }
+
+    unsigned int numImages, width, height;
+    if (!readMetaData(fp, &numImages, &width, &height))
+    {
+        fclos(fp);
+        return NULL;
+    }
+
+    if (!checkDimensions(width, height))
+    {
+        fclose(fp);
+        return NULL;
+    }
+
+    series = allocateSeriesStruct();
+    if (!series)
+    {
+        free(series);
+        fclose(fp);
+        return NULL;
+    }
+
+    if (!allocateImageAndLabelArrays(series, numImages, fp))
+    {
+        return NULL;
+    }
+
+    if (!allocateImageAndLabelImages(series, numImages, width, height, fp))
+    {
+        return NULL;
+    }
+
+    if (!readImagesAndLabels(fp, series, numImages, width, height))
+    {
+        return NULL;
+    }
+
+    return series;
+
+}   
+
+
 // TODO Vervollständigen Sie die Funktion clearSeries, welche eine Bildserie vollständig aus dem Speicher freigibt
 void clearSeries(GrayScaleImageSeries *series)
 {
+
 }