add some comments

.gitignore

@@ -2,4 +2,7 @@ mnist
 runTests
 *.o
 *.exe
-runMatrixTests
+runMatrixTests
+runImageInputTests
+runNeuralNetworkTests
+.vscode

imageInput.c

@@ -6,107 +6,165 @@
 #define BUFFER_SIZE 100
 #define FILE_HEADER_STRING "__info2_image_file_format__"
 
-//Datei öffnen, Header, Anzahl, Höhe und Breite lesen, geöffnete Datei zurückgeben
-static FILE* openAndReadShort (const char *path, unsigned short *count, unsigned short *width, unsigned short *height) {
-    FILE *file = fopen(path, "rb");
-    if (!file) {
-        return NULL;
-    }
-    size_t headerLength = strlen(FILE_HEADER_STRING);
-    char *header = malloc (headerLength + 1);
-    if(!header) {
-        return NULL;
-    }
+typedef enum
+{
+    IMG_SUCCESS = 0,
+    IMG_ERR_INVALID_HEADER, // Header did not match
+    IMG_ERR_READ,           // Failed to read from file, maybe it's too short
+    IMG_ERR,                // General Error
+} ImageError;
 
-    if (fread(header, sizeof(char), headerLength, file) != headerLength) {
-        free (header);
-        return NULL;
-    }
+static ImageError checkHeader(FILE *file);
+static ImageError readPictureParams(unsigned short *number, unsigned short *width, unsigned short *height, FILE *file);
+static ImageError readImage(size_t numPixels, GrayScalePixelType *pixelBuffer, unsigned char *label, FILE *file);
+static ImageError parseImageFile(FILE *file, GrayScaleImageSeries *series);
 
-    header[headerLength] = '\0';
-
-    if (strcmp (header, FILE_HEADER_STRING) != 0) {
-        free(header);
-        return NULL;
-    }
-    
-    free (header);
-
-    fread(count, sizeof(unsigned short), 1, file);
-    fread(width, sizeof(unsigned short), 1, file);
-    fread(height, sizeof(unsigned short), 1, file);
-
-    return file;
-}
-
-//Speicher anlegen und Pixel eines Bildes einlesen
-static GrayScaleImage* readPixles (FILE *file, unsigned short *width, unsigned short *height) {
-    GrayScaleImage *image = malloc (sizeof(GrayScaleImage));
-    image->width = *width;
-    image->height = *height;
-    image->buffer = malloc ((*width) * (*height) * sizeof(GrayScalePixelType));
-    if (!image->buffer) {
-        free(image);
-        return NULL;
-    }
-
-    for (unsigned int i = 0; i < (*width) * (*height); i++) {
-        unsigned char pixel;
-        if (fread(&pixel, sizeof(unsigned char), 1, file) != 1) {
-            free(image->buffer);
-            free(image);
-            return NULL;
-        }
-    image->buffer[i] = pixel;
-    }
-
-    return image;
-}
-
-//Ausführen von openAndReadShort, Anlegen des Speichers für Bilderserie, readPixles wird für jedes Bild ausgeführt
-//Nach jedem Bild wird das zugehörige Label gelesen, bei sämtlichen Fehlern wird NULL zurückgegeben und Speicher durch clearSeries bereinigt
 GrayScaleImageSeries *readImages(const char *path)
 {
-    unsigned short count = 0, width = 0, height = 0;
-
-    FILE *file = openAndReadShort(path, &count, &width, &height);
-    if (file == 0) {
+    // It's very important to call calloc here because otherwise clearSeries() might try to free random memory
+    GrayScaleImageSeries *series = calloc(1, sizeof(GrayScaleImageSeries));
+    if (series == NULL)
+    {
         return NULL;
     }
-    GrayScaleImageSeries *series = malloc(sizeof(GrayScaleImageSeries));
-    if (!series) {
-        fclose(file);
+
+    FILE *file = fopen(path, "rb");
+    // If fopen() failed
+    if (file == NULL)
+    {
+        clearSeries(series);
+        series = NULL;
         return NULL;
     }
-    series->count = count;
 
-    series->images = malloc(count * sizeof(GrayScaleImage));
-    series->labels = malloc(count* sizeof(unsigned char));
-
-    for (unsigned int i = 0; i < series->count; i++) {
-       GrayScaleImage *image = readPixles(file, &width, &height);
-       series->images[i] = *image;
-       free(image);
-
-       if (fread(&series->labels[i], sizeof(unsigned char), 1, file) != 1) {
-            clearSeries(series); 
-            fclose(file); 
-            return NULL; 
-        }
+    // Try to parse the whole file. If anything fails memory is freed
+    if (parseImageFile(file, series))
+    {
+        clearSeries(series);
+        series = NULL; // Return NULL after the file is properly closed 
     }
+
     fclose(file);
-    
     return series;
 }
 
-//Bereinigt den Speicher
-void clearSeries(GrayScaleImageSeries *series)
+static ImageError parseImageFile(FILE *file, GrayScaleImageSeries *series)
 {
-    for (unsigned int i = 0; i < series->count; i++) {
-        free(series->images[i].buffer);
+    if (checkHeader(file))
+    {
+        return IMG_ERR; // header check failed
     }
 
-    free(series->images);
-    free(series->labels);
-    free(series);
+    unsigned short imgCNT, width, height;
+    if (readPictureParams(&imgCNT, &width, &height, file))
+    {
+        return IMG_ERR; // read failed
+    }
+    size_t pixels = width * height;
+
+    // The images contain more pointers, definitely use calloc here
+    series->images = calloc(imgCNT, sizeof(GrayScaleImage));
+    if (series->images == NULL)
+    {
+        return IMG_ERR;
+    }
+
+    series->labels = malloc(imgCNT * sizeof(unsigned char));
+    if (series->labels == NULL)
+    {
+        return IMG_ERR;
+    }
+
+    series->count = imgCNT;
+    // Read every image and it's label
+    for (size_t imageIdx = 0; imageIdx < imgCNT; imageIdx++)
+    {
+        GrayScaleImage *curImage = &series->images[imageIdx];
+
+        curImage->buffer = malloc(sizeof(GrayScalePixelType) * pixels);
+        if (curImage->buffer == NULL)
+        {
+            return IMG_ERR;
+        }
+
+        curImage->width = width;
+        curImage->height = height;
+
+        if (readImage(pixels, curImage->buffer, &series->labels[imageIdx], file))
+        {
+            return IMG_ERR;
+        }
+    }
+    return IMG_SUCCESS;
+}
+
+static ImageError checkHeader(FILE *file)
+{
+    size_t len = strlen(FILE_HEADER_STRING);
+    char headerBuf[len + 1];
+    size_t charsRead = fread(headerBuf, 1, len, file);
+    // Check if the file is to short
+    if (charsRead < len)
+    {
+        return IMG_ERR_READ;
+    }
+    headerBuf[len] = '\0'; // Terminate string
+    return strcmp(headerBuf, FILE_HEADER_STRING) == 0 ? IMG_SUCCESS : IMG_ERR_INVALID_HEADER;
+}
+
+static ImageError readPictureParams(unsigned short *number, unsigned short *width, unsigned short *height, FILE *file)
+{
+    // number of images
+    if (1 != fread(number, sizeof(unsigned short), 1, file))
+    {
+        return IMG_ERR_READ;
+    }
+
+    // image width
+    if (1 != fread(width, sizeof(unsigned short), 1, file))
+    {
+        return IMG_ERR_READ;
+    }
+
+    // height
+    if (1 != fread(height, sizeof(unsigned short), 1, file))
+    {
+        return IMG_ERR_READ;
+    }
+
+    return IMG_SUCCESS;
+}
+
+// Read 1 image and it's label
+static ImageError readImage(size_t numPixels, GrayScalePixelType *pixelBuffer, unsigned char *label, FILE *file)
+{
+    if (numPixels > fread(pixelBuffer, sizeof(GrayScalePixelType), numPixels, file))
+    {
+        return IMG_ERR_READ;
+    }
+
+    if (1 != fread(label, sizeof(unsigned char), 1, file))
+    {
+        return IMG_ERR_READ;
+    }
+
+    return IMG_SUCCESS;
+}
+
+// Frees memory for each image buffer, image, label and finally series
+void clearSeries(GrayScaleImageSeries *series)
+{
+    if (series)
+    {
+
+        int seriesLen = series->count;
+        for (size_t imageIdx = 0; imageIdx < seriesLen; imageIdx++)
+        {
+            free(series->images[imageIdx].buffer);
+        }
+
+        free(series->images);
+        free(series->labels);
+        free(series);
+    }
 }

matrix.c

@@ -67,18 +67,14 @@ Matrix add(const Matrix matrix1, const Matrix matrix2)
         return createMatrix(0, 0);
     }
 
-    // matrices not compatible
-    if (matrix1.rows != matrix2.rows)
-    {
-        clearMatrix(&resMat);
-        return resMat;
-    }
-
-    // check if broadcasting is possible
     if (matrix1.cols != matrix2.cols)
     {
-        // matrix1 is a vector
-        if (matrix1.cols == 1)
+        if (matrix1.rows != matrix2.rows)
+        {
+            clearMatrix(&resMat);
+            return resMat;
+        }
+        else if (matrix1.cols == 1)
         {
             // broadcast vector
             for (size_t m = 0; m < matrix2.rows; m++)
@@ -90,7 +86,6 @@ Matrix add(const Matrix matrix1, const Matrix matrix2)
             }
             return resMat;
         }
-        // matrix2 is a vector
         else if (matrix2.cols == 1)
         {
             // broadcast vector
@@ -103,7 +98,6 @@ Matrix add(const Matrix matrix1, const Matrix matrix2)
             }
             return resMat;
         }
-        // addition not possible
         else
         {
             clearMatrix(&resMat);
@@ -115,7 +109,6 @@ Matrix add(const Matrix matrix1, const Matrix matrix2)
     {
         for (size_t n = 0; n < matrix1.cols; n++)
         {
-            // this is unnecessarily complicated because at this point we already know that the matrices are compatible
             setMatrixAt(getMatrixAt(matrix1, m, n) + getMatrixAt(matrix2, m, n), resMat, m, n);
         }
     }
@@ -123,32 +116,37 @@ Matrix add(const Matrix matrix1, const Matrix matrix2)
     return resMat;
 }
 
-Matrix multiply(const Matrix matrix1, const Matrix matrix2)
+Matrix multiply(const Matrix A, const Matrix B)
 {
-    if (matrix1.cols != matrix2.rows || matrix1.buffer == NULL || matrix2.buffer == NULL)
+    if (A.cols != B.rows || A.buffer == NULL || B.buffer == NULL)
     {
         return createMatrix(0, 0);
     }
 
-    int rows = matrix1.rows, cols = matrix2.cols;
-    Matrix resMat = createMatrix(rows, cols);
+    int rows = A.rows, cols = B.cols;
+    Matrix C = createMatrix(rows, cols);
 
-    if (resMat.buffer == NULL)
+    if (C.buffer == NULL)
     {
         return createMatrix(0, 0);
     }
 
-    for (size_t rowIdx = 0; rowIdx < rows; rowIdx++)
+    // M = Rows, K = Common Dim, N = Cols
+    size_t M = A.rows, K = A.cols, N = B.cols;
+
+    for (size_t i = 0; i < M; i++)
     {
-        for (size_t colIdx = 0; colIdx < cols; colIdx++)
+        for (size_t k = 0; k < K; k++)
+
         {
-            int curCellVal = 0;
-            for (size_t k = 0; k < matrix1.cols; k++)
+            MatrixType valA = A.buffer[i * K + k];
+            for (size_t j = 0; j < N; j++)
             {
-                curCellVal += getMatrixAt(matrix1, rowIdx, k) * getMatrixAt(matrix2, k, colIdx);
+                // C[i, j] += A[i, k] * B[k, j];
+                // M x N,     M x K,    K x N
+                C.buffer[i * N + j] += valA * B.buffer[k * N + j];
             }
-            setMatrixAt(curCellVal, resMat, rowIdx, colIdx);
         }
     }
-    return resMat;
+    return C;
 }

matrix.h

@@ -8,9 +8,10 @@ typedef float MatrixType;
 // Matrixtyp
 typedef struct Matrix
 {
-    MatrixType *buffer;
     size_t rows;
     size_t cols;
+    MatrixType *buffer;
+
 } Matrix;
 
 Matrix createMatrix(unsigned int rows, unsigned int cols);

neuralNetworkTests.c

@@ -5,44 +5,29 @@
 #include "unity.h"
 #include "neuralNetwork.h"
 
-static void writeLayer(FILE *file, const Matrix weights, const Matrix biases, unsigned int inputDim)
+
+static void erzeugeMatrix(FILE *file, const Matrix *m)
 {
-    unsigned int outputDim = (unsigned int)weights.rows;
-    fwrite(&outputDim, sizeof(unsigned int), 1, file);
-    if (weights.buffer != NULL)
-        fwrite(weights.buffer, sizeof(MatrixType), outputDim * inputDim, file);
-
-    if (biases.buffer != NULL)
-        fwrite(biases.buffer, sizeof(MatrixType), outputDim, file);
+    fwrite(&m->rows, sizeof(int), 1, file);
+    fwrite(&m->cols, sizeof(int), 1, file);
+    fwrite(m->buffer, sizeof(MatrixType), m->rows * m->cols, file);
 }
 
-
 static void prepareNeuralNetworkFile(const char *path, const NeuralNetwork nn)
 {
     FILE *file = fopen(path, "wb");
-    if (!file) return;
-
-    const char tag[] = "__info2_neural_network_file_format__";
-    fwrite(tag, sizeof(char), strlen(tag), file);
-
-    if (nn.numberOfLayers == 0)
-    {
-        unsigned int zero = 0;
-        fwrite(&zero, sizeof(unsigned int), 1, file);
-        fclose(file);
+    if (!file)
         return;
-    }
 
-    unsigned int inputDim = (unsigned int)nn.layers[0].weights.cols;
-    fwrite(&inputDim, sizeof(unsigned int), 1, file);
+    const char *header = "__info2_neural_network_file_format__";
+    fwrite(header, sizeof(char), strlen(header), file);
+    fwrite(&nn.numberOfLayers, sizeof(int), 1, file);
 
     for (int i = 0; i < nn.numberOfLayers; i++)
     {
-        writeLayer(file, nn.layers[i].weights, nn.layers[i].biases, inputDim);
-        inputDim = (unsigned int)nn.layers[i].weights.rows;
+        erzeugeMatrix(file, &nn.layers[i].weights);
+        erzeugeMatrix(file, &nn.layers[i].biases);
     }
-    unsigned int zero = 0;
-    fwrite(&zero, sizeof(unsigned int), 1, file);
 
     fclose(file);
 }

testFile.info2

@@ -1 +0,0 @@
-some_tag