diff --git a/samples/python2/digits.png b/samples/python2/digits.png new file mode 100644 index 0000000000..01cdd2972c Binary files /dev/null and b/samples/python2/digits.png differ diff --git a/samples/python2/digits.py b/samples/python2/digits.py new file mode 100644 index 0000000000..c3494c0bb4 --- /dev/null +++ b/samples/python2/digits.py @@ -0,0 +1,89 @@ +import numpy as np +import cv2 +import itertools as it + +''' +from scipy.io import loadmat + +m = loadmat('ex4data1.mat') +X = m['X'].reshape(-1, 20, 20) +X = np.transpose(X, (0, 2, 1)) +img = np.vstack(map(np.hstack, X.reshape(-1, 100, 20, 20))) +img = np.uint8(np.clip(img, 0, 1)*255) +cv2.imwrite('digits.png', img) +''' + +def unroll_responses(responses, class_n): + sample_n = len(responses) + new_responses = np.zeros((sample_n, class_n), np.float32) + new_responses[np.arange(sample_n), responses] = 1 + return new_responses + + +SZ = 20 +digits_img = cv2.imread('digits.png', 0) + +h, w = digits_img.shape +digits = [np.hsplit(row, w/SZ) for row in np.vsplit(digits_img, h/SZ)] +digits = np.float32(digits).reshape(-1, SZ*SZ) +N = len(digits) +labels = np.repeat(np.arange(10), N/10) + +shuffle = np.random.permutation(N) +train_n = int(0.9*N) + +digits_train, digits_test = np.split(digits[shuffle], [train_n]) +labels_train, labels_test = np.split(labels[shuffle], [train_n]) + +labels_train_unrolled = unroll_responses(labels_train, 10) + +model = cv2.ANN_MLP() +layer_sizes = np.int32([SZ*SZ, 25, 10]) +model.create(layer_sizes) + +# CvANN_MLP_TrainParams::BACKPROP,0.001 +params = dict( term_crit = (cv2.TERM_CRITERIA_COUNT, 300, 0.01), + train_method = cv2.ANN_MLP_TRAIN_PARAMS_BACKPROP, + bp_dw_scale = 0.001, + bp_moment_scale = 0.0 ) +print 'training...' +model.train(digits_train, labels_train_unrolled, None, params=params) +model.save('dig_nn.dat') +model.load('dig_nn.dat') + +ret, resp = model.predict(digits_test) +resp = resp.argmax(-1) +error_mask = (resp == labels_test) +print error_mask.mean() + +def grouper(n, iterable, fillvalue=None): + "grouper(3, 'ABCDEFG', 'x') --> ABC DEF Gxx" + args = [iter(iterable)] * n + return it.izip_longest(fillvalue=fillvalue, *args) + +def mosaic(w, imgs): + imgs = iter(imgs) + img0 = imgs.next() + pad = np.zeros_like(img0) + imgs = it.chain([img0], imgs) + rows = grouper(w, imgs, pad) + return np.vstack(map(np.hstack, rows)) + +test_img = np.uint8(digits_test).reshape(-1, SZ, SZ) + +def vis_resp(img, flag): + img = cv2.cvtColor(img, cv2.COLOR_GRAY2BGR) + if not flag: + img[...,:2] = 0 + return img + +test_img = mosaic(25, it.starmap(vis_resp, it.izip(test_img, error_mask))) +cv2.imshow('test', test_img) +cv2.waitKey() + + + + + + +