forked from freudenreichan/info2Praktikum-NeuronalesNetz
144 lines
4.0 KiB
C
144 lines
4.0 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include "imageInput.h"
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#define BUFFER_SIZE 100
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#define FILE_HEADER_STRING "mnist_model.info2"
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// TODO Implementieren Sie geeignete Hilfsfunktionen für das Lesen der Bildserie aus einer Datei
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static int checkFileHeader(FILE* f) {
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char buffer[BUFFER_SIZE];
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size_t len = strlen(FILE_HEADER_STRING);
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if (fread(buffer, 1, len, f) != len) {
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return -1; // Fehler beim Lesen
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}
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buffer[len] = '\0';
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return strcmp(buffer, FILE_HEADER_STRING) == 0 ? 0 : -1;
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}
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static int readImageMeta(FILE* f, unsigned short* count, unsigned short* width, unsigned short* height) {
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if (fread(count, sizeof(unsigned short), 1, f) != 1) return -1;
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if (fread(width, sizeof(unsigned short), 1, f) != 1) return -1;
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if (fread(height, sizeof(unsigned short), 1, f) != 1) return -1;
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return 0;
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}
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static GrayScaleImage readSingleImage(FILE* f, unsigned short width, unsigned short height) {
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GrayScaleImage img;
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// Breite und Höhe setzen
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img.width = width;
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img.height = height;
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// Speicher für Pixel reservieren
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size_t pixelCount = (size_t)width * (size_t)height;
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img.buffer = malloc(pixelCount * sizeof(GrayScalePixelType));
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if (img.buffer == NULL) {
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// Fehlerfall: kein Speicher
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img.width = 0;
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img.height = 0;
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return img;
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}
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}
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static GrayScaleImageSeries readImageSeries(FILE* f, unsigned short count, unsigned short width, unsigned short height) {
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GrayScaleImageSeries series;
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// Anzahl der Bilder speichern
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series.count = count;
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// Speicher für Bilder und Labels reservieren
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series.images = malloc(count * sizeof(GrayScaleImage));
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series.labels = malloc(count * sizeof(unsigned char));
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if (series.images == NULL || series.labels == NULL) {
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// Fehlerfall: kein Speicher
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series.count = 0;
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series.images = NULL;
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series.labels = NULL;
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return series;
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}
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// Alle Bilder und Labels einlesen
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for (unsigned short i = 0; i < count; i++) {
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series.images[i] = readSingleImage(f, width, height);
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// Label separat lesen
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if (fread(&series.labels[i], sizeof(unsigned char), 1, f) != 1) {
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series.labels[i] = 0; // Fehlerfall: Default-Label
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}
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}
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return series;
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}
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// Test
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// TODO Vervollständigen Sie die Funktion readImages unter Benutzung Ihrer Hilfsfunktionen
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GrayScaleImageSeries *readImages(const char *path)
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{
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FILE *f = fopen(path, "rb");
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if (f == NULL) {
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return NULL; // Datei konnte nicht geöffnet werden
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}
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// 1. Header prüfen
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if (checkFileHeader(f) != 0) {
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fclose(f);
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return NULL; // falsches Dateiformat
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}
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// 2. Metadaten lesen (Anzahl, Breite, Höhe)
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unsigned short count, width, height;
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if (readImageMeta(f, &count, &width, &height) != 0) {
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fclose(f);
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return NULL; // Metadaten konnten nicht gelesen werden
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}
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// 3. Speicher für Serie reservieren
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GrayScaleImageSeries *series = malloc(sizeof(GrayScaleImageSeries));
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if (series == NULL) {
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fclose(f);
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return NULL; // Speicherfehler
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}
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series->count = count;
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series->images = malloc(count * sizeof(GrayScaleImage));
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series->labels = malloc(count * sizeof(unsigned char));
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if (series->images == NULL || series->labels == NULL) {
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free(series->images);
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free(series->labels);
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free(series);
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fclose(f);
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return NULL;
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}
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// 4. Bilder + Labels einlesen
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for (unsigned short i = 0; i < count; i++) {
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series->images[i] = readSingleImage(f, width, height);
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if (fread(&series->labels[i], sizeof(unsigned char), 1, f) != 1) {
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// Fehler beim Label-Lesen → Serie freigeben
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clearSeries(series);
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fclose(f);
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return NULL;
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}
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}
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fclose(f);
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return series;
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}
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// TODO Vervollständigen Sie die Funktion clearSeries, welche eine Bildserie vollständig aus dem Speicher freigibt
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void clearSeries(GrayScaleImageSeries *series)
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{
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} |