fix image input.c

imageInput.c

@@ -7,94 +7,131 @@
 #define FILE_HEADER_STRING "__info2_image_file_format__"
 
 
-/// @brief Gets the next char value from specified and opened file
+/// @brief Reads a value in little-endian format from file
 /// @param openedFile stream FILE, from which to read
-/// @param iterations how many chars are being taken from (1 char equals 2 Hexdecimals equals 8bit)
+/// @param bytes how many bytes to read
-static int getCharValueFromFile(FILE* openedFile, int iterations) {
+static unsigned int readLittleEndian(FILE* openedFile, int bytes) {
-    int addToFile = 0;
+    unsigned int value = 0;
 
     if (openedFile == NULL) return 0;
 
-    for (int i = 0; i < iterations; i++) {
+    for (int i = 0; i < bytes; i++) {
         int tmp = fgetc(openedFile);
-        //If the File ends, the method returns a '0'
+        if (tmp == EOF) return 0;
-        if (openedFile == EOF) return addToFile;
+        
-
+        value |= ((unsigned int)tmp) << (i * 8);
-        addToFile += tmp; 
     }
 
-    return addToFile;
+    return value;
 }
 
 // TODO Vervollständigen Sie die Funktion readImages unter Benutzung Ihrer Hilfsfunktionen
 GrayScaleImageSeries *readImages(const char *path)
 {
-    GrayScaleImageSeries *series = NULL;
+    FILE* openFile = fopen(path, "rb");
-
-    FILE* openFile;
-
-    openFile = fopen(path, "rb");
 
     // file Could not be opened/does not exist
-    if (openFile != NULL) {
+    if (openFile == NULL) {
+        return NULL;
+    }
 
-         char* actualFileTag = malloc(strlen(FILE_HEADER_STRING) * sizeof(char));
+    char actualFileTag[strlen(FILE_HEADER_STRING) + 1];
-         int numberOfImages = 0;
+    
-         int width = 0;
+    size_t tagLength = strlen(FILE_HEADER_STRING);
-         int height = 0;
+    if (fread(actualFileTag, 1, tagLength, openFile) != tagLength) {
+        fclose(openFile);
+        return NULL;
+    }
+    actualFileTag[tagLength] = '\0';
 
-        for (int i = 0; i < strlen(FILE_HEADER_STRING); i++) {
+    // checks if the files are equal
-            actualFileTag += fgetc(openFile);
+    if (strcmp(actualFileTag, FILE_HEADER_STRING) != 0) {
+        fclose(openFile);
+        return NULL;
+    }
+
+    unsigned int numberOfImages = readLittleEndian(openFile, 2);
+
+    // no Images in series -> No image-series
+    if (numberOfImages == 0) {
+        fclose(openFile);
+        return NULL;
+    }
+
+    unsigned int width  = readLittleEndian(openFile, 2);
+    unsigned int height = readLittleEndian(openFile, 2);
+
+    // no height/width --> impossible file 
+    if(height == 0 || width == 0) {
+        fclose(openFile);
+        return NULL;
+    }
+
+    //all the starting parameters are set --> the images can be read and stored
+    GrayScaleImageSeries* series = malloc(sizeof(GrayScaleImageSeries));
+    if (series == NULL) {
+        fclose(openFile);
+        return NULL;
+    }
+
+    GrayScaleImage* images = malloc(numberOfImages * sizeof(GrayScaleImage));
+    unsigned char* labels = malloc(numberOfImages * sizeof(unsigned char));
+
+    if (images == NULL || labels == NULL) {
+        free(images);
+        free(labels);
+        free(series);
+        fclose(openFile);
+        return NULL;
+    }
+
+    series->count = 0;
+    series->images = images;
+    series->labels = labels;
+
+    for (unsigned int i = 0; i < numberOfImages; i++) {
+        // allocating the actual matrix image for each image
+        images[i].buffer = malloc(width * height);
+        
+        if (images[i].buffer == NULL) {
+            for (unsigned int k = 0; k < i; k++) {
+                free(images[k].buffer);
+            }
+            free(images);
+            free(labels);
+            free(series);
+            fclose(openFile);
+            return NULL;
         }
 
-        // checks if the files are equal: strcmp should return '0' --> convert it to '1' for 'true'
+        images[i].height = height;
-        int fileTagEqual = !strcmp(actualFileTag, FILE_HEADER_STRING);
+        images[i].width = width;
 
-        //we only need the fileTag to verify its an image for our series.
+        if (fread(images[i].buffer, 1, width * height, openFile) != width * height) {
-        free(actualFileTag);
+            for (unsigned int k = 0; k <= i; k++) {
-        actualFileTag = NULL;
+                free(images[k].buffer);
-
-
-        if (fileTagEqual) {
-            numberOfImages = getCharValueFromFile(openFile, 2);
-
-            // no Images in series -> No image-series
-            if (numberOfImages == 0) {
-                fclose(openFile);
-                return series;
-            }
-
-            width  = getCharValueFromFile(openFile, 2);
-            height = getCharValueFromFile(openFile, 2);
-
-            // no height/width --> impossible file 
-            if(height == 0 || width == 0) {
-                fclose(openFile);
-                return series;
-            }
-
-            //all the starting parameters are set --> the images can be read and stored
-            GrayScaleImage* images = malloc(numberOfImages * sizeof(GrayScaleImage));
-            unsigned char* labels = malloc(numberOfImages * sizeof(unsigned char));
-
-            series->count = 0;
-            series->images = images;
-            series->labels = labels;
-
-            for (int i = 0; i < numberOfImages; i++) {
-                for (int j = 0; j < width * height; j++) {
-                    // allocating the actual matrix image for image
-                    images[i].buffer = malloc(width * height);
-
-                    images[i].height = height;
-                    images[i].width = width;
-                    images[i].buffer[j] = fgetc(openFile);
-                }
-                //rest of the values that only affect the image itself
-                series->labels[i] = fgetc(openFile);
-                series->count++;
             }
+            free(images);
+            free(labels);
+            free(series);
+            fclose(openFile);
+            return NULL;
         }
+        
+        //rest of the values that only affect the image itself
+        int label = fgetc(openFile);
+        if (label == EOF) {
+            for (unsigned int k = 0; k <= i; k++) {
+                free(images[k].buffer);
+            }
+            free(images);
+            free(labels);
+            free(series);
+            fclose(openFile);
+            return NULL;
+        }
+        series->labels[i] = (unsigned char)label;
+        series->count++;
     }
 
     fclose(openFile);
@@ -104,12 +141,13 @@ GrayScaleImageSeries *readImages(const char *path)
 // TODO Vervollständigen Sie die Funktion clearSeries, welche eine Bildserie vollständig aus dem Speicher freigibt
 void clearSeries(GrayScaleImageSeries *series)
 {
+    if (series == NULL) return;
+
     for (int i = 0; i < series->count; i++) {
         free(series->images[i].buffer);
     }
 
     free(series->images);
-    series->images = NULL;
     free(series->labels);
-    series->labels = NULL;
+    free(series);
 }

imageInput_old.c

@@ -0,0 +1,115 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "imageInput.h"
+
+#define BUFFER_SIZE 100
+#define FILE_HEADER_STRING "__info2_image_file_format__"
+
+
+/// @brief Gets the next char value from specified and opened file
+/// @param openedFile stream FILE, from which to read
+/// @param iterations how many chars are being taken from (1 char equals 2 Hexdecimals equals 8bit)
+static int getCharValueFromFile(FILE* openedFile, int iterations) {
+    int addToFile = 0;
+
+    if (openedFile == NULL) return 0;
+
+    for (int i = 0; i < iterations; i++) {
+        int tmp = fgetc(openedFile);
+        //If the File ends, the method returns a '0'
+        if (openedFile == EOF) return addToFile;
+
+        addToFile += tmp; 
+    }
+
+    return addToFile;
+}
+
+// TODO Vervollständigen Sie die Funktion readImages unter Benutzung Ihrer Hilfsfunktionen
+GrayScaleImageSeries *readImages(const char *path)
+{
+    GrayScaleImageSeries *series = NULL;
+
+    FILE* openFile;
+
+    openFile = fopen(path, "rb");
+
+    // file Could not be opened/does not exist
+    if (openFile != NULL) {
+
+         char* actualFileTag = malloc(strlen(FILE_HEADER_STRING) * sizeof(char));
+         int numberOfImages = 0;
+         int width = 0;
+         int height = 0;
+
+        for (int i = 0; i < strlen(FILE_HEADER_STRING); i++) {
+            actualFileTag += fgetc(openFile);
+        }
+
+        // checks if the files are equal: strcmp should return '0' --> convert it to '1' for 'true'
+        int fileTagEqual = !strcmp(actualFileTag, FILE_HEADER_STRING);
+
+        //we only need the fileTag to verify its an image for our series.
+        free(actualFileTag);
+        actualFileTag = NULL;
+
+
+        if (fileTagEqual) {
+            numberOfImages = getCharValueFromFile(openFile, 2);
+
+            // no Images in series -> No image-series
+            if (numberOfImages == 0) {
+                fclose(openFile);
+                return series;
+            }
+
+            width  = getCharValueFromFile(openFile, 2);
+            height = getCharValueFromFile(openFile, 2);
+
+            // no height/width --> impossible file 
+            if(height == 0 || width == 0) {
+                fclose(openFile);
+                return series;
+            }
+
+            //all the starting parameters are set --> the images can be read and stored
+            GrayScaleImage* images = malloc(numberOfImages * sizeof(GrayScaleImage));
+            unsigned char* labels = malloc(numberOfImages * sizeof(unsigned char));
+
+            series->count = 0;
+            series->images = images;
+            series->labels = labels;
+
+            for (int i = 0; i < numberOfImages; i++) {
+                for (int j = 0; j < width * height; j++) {
+                    // allocating the actual matrix image for image
+                    images[i].buffer = malloc(width * height);
+
+                    images[i].height = height;
+                    images[i].width = width;
+                    images[i].buffer[j] = fgetc(openFile);
+                }
+                //rest of the values that only affect the image itself
+                series->labels[i] = fgetc(openFile);
+                series->count++;
+            }
+        }
+    }
+
+    fclose(openFile);
+    return series;
+}
+
+// TODO Vervollständigen Sie die Funktion clearSeries, welche eine Bildserie vollständig aus dem Speicher freigibt
+void clearSeries(GrayScaleImageSeries *series)
+{
+    for (int i = 0; i < series->count; i++) {
+        free(series->images[i].buffer);
+    }
+
+    free(series->images);
+    series->images = NULL;
+    free(series->labels);
+    series->labels = NULL;
+}