private void readPrefixes(BufferedReader reader, ImageBuilder imgBuilder)
			throws IOException {
		int tokenCounter = 1;

		while (tokenCounter < 5) {
			String line = trimLine(reader.readLine());
			if (line.equals("")) {
				continue;
			} else {
				String[] tokens = line.split(PIXEL_DELIMITER);
				for (int i = 0; i < tokens.length; i++, tokenCounter++) {
					if (tokenCounter == 4) {
						imgBuilder.setMaximumGreyScaleValue(Short
								.parseShort(tokens[i]));
					}
				}
			}
		}

		if (tokenCounter > 5) {
			System.out
					.println("File began on same line as the greyscale value. Import will not work properly!");
		}

	}