Read the barcode. The image must be an 8-bit gray image. The other parameters specify a cropping window. The barcode should almost fill the cropping window. The barcode will be located and rectified in the window. It is assumed to extend horizontally across the window. The resulting barcode, if read, will be returned from getCode(). getSuccessful() can be queried to determine whether the barcode was successfully read.
The image is cropped as all pixels whose position is greater than or equal to the top or left, and less than the bottom and right.
@param image the input image.
@throws jjil.core.Error if the barcode rectangle is outside the image, or the input image is notan RgbImage.