python识别验证码的库pytesser

"""OCR in Python using the Tesseract engine from Google http://code.google.com/p/pytesser/ by Michael J.T. O'Kelly V 0.0.1, 3/10/07""" import Image import subprocess import util import errors tesseract_exe_name = 'tesseract' # Name of executable to be called at command line scratch_image_name = "temp.bmp" # This file must be .bmp or other Tesseract-compatible format scratch_text_name_root = "temp" # Leave out the .txt extension cleanup_scratch_flag = True # Temporary files cleaned up after OCR operation def call_tesseract(input_filename, output_filename): """Calls external tesseract.exe on input file (restrictions on types), outputting output_filename+'txt'""" args = [tesseract_exe_name, input_filename, output_filename] proc = subprocess.Popen(args) retcode = proc.wait() if retcode!=0: errors.check_for_errors() def image_to_string(im, cleanup = cleanup_scratch_flag): """Converts im to file, applies tesseract, and fetches resulting text. If cleanup=True, delete scratch files after operation.""" try: util.image_to_scratch(im, scratch_image_name) call_tesseract(scratch_image_name, scratch_text_name_root) text = util.retrieve_text(scratch_text_name_root) finally: if cleanup: util.perform_cleanup(scratch_image_name, scratch_text_name_root) return text def image_file_to_string(filename, cleanup = cleanup_scratch_flag, graceful_errors=True): """Applies tesseract to filename; or, if image is incompatible and graceful_errors=True, converts to compatible format and then applies tesseract. Fetches resulting text. If cleanup=True, delete scratch files after operation.""" try: try: call_tesseract(filename, scratch_text_name_root) text = util.retrieve_text(scratch_text_name_root) except errors.Tesser_General_Exception: if graceful_errors: im = Image.open(filename) text = image_to_string(im, cleanup) else: raise finally: if cleanup: util.perform_cleanup(scratch_image_name, scratch_text_name_root) return text if __name__=='__main__': im = Image.open('phototest.tif') text = image_to_string(im) print text try: text = image_file_to_string('fnord.tif', graceful_errors=False) except errors.Tesser_General_Exception, value: print "fnord.tif is incompatible filetype. Try graceful_errors=True" print value text = image_file_to_string('fnord.tif', graceful_errors=True) print "fnord.tif contents:", text text = image_file_to_string('fonts_test.png', graceful_errors=True) print text