#!/usr/bin/env python ''' The sample demonstrates how to train Random Trees classifier (or Boosting classifier, or MLP, or Knearest, or Support Vector Machines) using the provided dataset. We use the sample database letter-recognition.data from UCI Repository, here is the link: Newman, D.J. & Hettich, S. & Blake, C.L. & Merz, C.J. (1998). UCI Repository of machine learning databases [http://www.ics.uci.edu/~mlearn/MLRepository.html]. Irvine, CA: University of California, Department of Information and Computer Science. The dataset consists of 20000 feature vectors along with the responses - capital latin letters A..Z. The first 10000 samples are used for training and the remaining 10000 - to test the classifier. ====================================================== USAGE: letter_recog.py [--model ] [--data ] [--load ] [--save ] Models: RTrees, KNearest, Boost, SVM, MLP ''' # Python 2/3 compatibility from __future__ import print_function import numpy as np import cv2 as cv def load_base(fn): a = np.loadtxt(fn, np.float32, delimiter=',', converters={ 0 : lambda ch : ord(ch)-ord('A') }) samples, responses = a[:,1:], a[:,0] return samples, responses class LetterStatModel(object): class_n = 26 train_ratio = 0.5 def load(self, fn): self.model = self.model.load(fn) def save(self, fn): self.model.save(fn) def unroll_samples(self, samples): sample_n, var_n = samples.shape new_samples = np.zeros((sample_n * self.class_n, var_n+1), np.float32) new_samples[:,:-1] = np.repeat(samples, self.class_n, axis=0) new_samples[:,-1] = np.tile(np.arange(self.class_n), sample_n) return new_samples def unroll_responses(self, responses): sample_n = len(responses) new_responses = np.zeros(sample_n*self.class_n, np.int32) resp_idx = np.int32( responses + np.arange(sample_n)*self.class_n ) new_responses[resp_idx] = 1 return new_responses class RTrees(LetterStatModel): def __init__(self): self.model = cv.ml.RTrees_create() def train(self, samples, responses): self.model.setMaxDepth(20) self.model.train(samples, cv.ml.ROW_SAMPLE, responses.astype(int)) def predict(self, samples): _ret, resp = self.model.predict(samples) return resp.ravel() class KNearest(LetterStatModel): def __init__(self): self.model = cv.ml.KNearest_create() def train(self, samples, responses): self.model.train(samples, cv.ml.ROW_SAMPLE, responses) def predict(self, samples): _retval, results, _neigh_resp, _dists = self.model.findNearest(samples, k = 10) return results.ravel() class Boost(LetterStatModel): def __init__(self): self.model = cv.ml.Boost_create() def train(self, samples, responses): _sample_n, var_n = samples.shape new_samples = self.unroll_samples(samples) new_responses = self.unroll_responses(responses) var_types = np.array([cv.ml.VAR_NUMERICAL] * var_n + [cv.ml.VAR_CATEGORICAL, cv.ml.VAR_CATEGORICAL], np.uint8) self.model.setWeakCount(15) self.model.setMaxDepth(10) self.model.train(cv.ml.TrainData_create(new_samples, cv.ml.ROW_SAMPLE, new_responses.astype(int), varType = var_types)) def predict(self, samples): new_samples = self.unroll_samples(samples) _ret, resp = self.model.predict(new_samples) return resp.ravel().reshape(-1, self.class_n).argmax(1) class SVM(LetterStatModel): def __init__(self): self.model = cv.ml.SVM_create() def train(self, samples, responses): self.model.setType(cv.ml.SVM_C_SVC) self.model.setC(1) self.model.setKernel(cv.ml.SVM_RBF) self.model.setGamma(.1) self.model.train(samples, cv.ml.ROW_SAMPLE, responses.astype(int)) def predict(self, samples): _ret, resp = self.model.predict(samples) return resp.ravel() class MLP(LetterStatModel): def __init__(self): self.model = cv.ml.ANN_MLP_create() def train(self, samples, responses): _sample_n, var_n = samples.shape new_responses = self.unroll_responses(responses).reshape(-1, self.class_n) layer_sizes = np.int32([var_n, 100, 100, self.class_n]) self.model.setLayerSizes(layer_sizes) self.model.setTrainMethod(cv.ml.ANN_MLP_BACKPROP) self.model.setBackpropMomentumScale(0.0) self.model.setBackpropWeightScale(0.001) self.model.setTermCriteria((cv.TERM_CRITERIA_COUNT, 20, 0.01)) self.model.setActivationFunction(cv.ml.ANN_MLP_SIGMOID_SYM, 2, 1) self.model.train(samples, cv.ml.ROW_SAMPLE, np.float32(new_responses)) def predict(self, samples): _ret, resp = self.model.predict(samples) return resp.argmax(-1) if __name__ == '__main__': import getopt import sys print(__doc__) models = [RTrees, KNearest, Boost, SVM, MLP] # NBayes models = dict( [(cls.__name__.lower(), cls) for cls in models] ) args, dummy = getopt.getopt(sys.argv[1:], '', ['model=', 'data=', 'load=', 'save=']) args = dict(args) args.setdefault('--model', 'svm') args.setdefault('--data', 'letter-recognition.data') datafile = cv.samples.findFile(args['--data']) print('loading data %s ...' % datafile) samples, responses = load_base(datafile) Model = models[args['--model']] model = Model() train_n = int(len(samples)*model.train_ratio) if '--load' in args: fn = args['--load'] print('loading model from %s ...' % fn) model.load(fn) else: print('training %s ...' % Model.__name__) model.train(samples[:train_n], responses[:train_n]) print('testing...') train_rate = np.mean(model.predict(samples[:train_n]) == responses[:train_n].astype(int)) test_rate = np.mean(model.predict(samples[train_n:]) == responses[train_n:].astype(int)) print('train rate: %f test rate: %f' % (train_rate*100, test_rate*100)) if '--save' in args: fn = args['--save'] print('saving model to %s ...' % fn) model.save(fn) cv.destroyAllWindows()