diff --git a/imageInput.c b/imageInput.c index bb30de1..2174990 100644 --- a/imageInput.c +++ b/imageInput.c @@ -6,17 +6,110 @@ #define BUFFER_SIZE 100 #define FILE_HEADER_STRING "__info2_image_file_format__" -// TODO Implementieren Sie geeignete Hilfsfunktionen für das Lesen der Bildserie aus einer Datei + +/// @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; } \ No newline at end of file