#!/usr/bin/env python ''' This module contains some common routines used by other samples. ''' import numpy as np import cv2 as cv # built-in modules import os import itertools as it from contextlib import contextmanager image_extensions = ['.bmp', '.jpg', '.jpeg', '.png', '.tif', '.tiff', '.pbm', '.pgm', '.ppm'] class Bunch(object): def __init__(self, **kw): self.__dict__.update(kw) def __str__(self): return str(self.__dict__) def splitfn(fn): path, fn = os.path.split(fn) name, ext = os.path.splitext(fn) return path, name, ext def anorm2(a): return (a*a).sum(-1) def anorm(a): return np.sqrt( anorm2(a) ) def homotrans(H, x, y): xs = H[0, 0]*x + H[0, 1]*y + H[0, 2] ys = H[1, 0]*x + H[1, 1]*y + H[1, 2] s = H[2, 0]*x + H[2, 1]*y + H[2, 2] return xs/s, ys/s def to_rect(a): a = np.ravel(a) if len(a) == 2: a = (0, 0, a[0], a[1]) return np.array(a, np.float64).reshape(2, 2) def rect2rect_mtx(src, dst): src, dst = to_rect(src), to_rect(dst) cx, cy = (dst[1] - dst[0]) / (src[1] - src[0]) tx, ty = dst[0] - src[0] * (cx, cy) M = np.float64([[ cx, 0, tx], [ 0, cy, ty], [ 0, 0, 1]]) return M def lookat(eye, target, up = (0, 0, 1)): fwd = np.asarray(target, np.float64) - eye fwd /= anorm(fwd) right = np.cross(fwd, up) right /= anorm(right) down = np.cross(fwd, right) R = np.float64([right, down, fwd]) tvec = -np.dot(R, eye) return R, tvec def mtx2rvec(R): w, u, vt = cv.SVDecomp(R - np.eye(3)) p = vt[0] + u[:,0]*w[0] # same as np.dot(R, vt[0]) c = np.dot(vt[0], p) s = np.dot(vt[1], p) axis = np.cross(vt[0], vt[1]) return axis * np.arctan2(s, c) def draw_str(dst, (x, y), s): cv.putText(dst, s, (x+1, y+1), cv.FONT_HERSHEY_PLAIN, 1.0, (0, 0, 0), thickness = 2, lineType=cv.LINE_AA) cv.putText(dst, s, (x, y), cv.FONT_HERSHEY_PLAIN, 1.0, (255, 255, 255), lineType=cv.LINE_AA) class Sketcher: def __init__(self, windowname, dests, colors_func): self.prev_pt = None self.windowname = windowname self.dests = dests self.colors_func = colors_func self.dirty = False self.show() cv.setMouseCallback(self.windowname, self.on_mouse) def show(self): cv.imshow(self.windowname, self.dests[0]) def on_mouse(self, event, x, y, flags, param): pt = (x, y) if event == cv.EVENT_LBUTTONDOWN: self.prev_pt = pt elif event == cv.EVENT_LBUTTONUP: self.prev_pt = None if self.prev_pt and flags & cv.EVENT_FLAG_LBUTTON: for dst, color in zip(self.dests, self.colors_func()): cv.line(dst, self.prev_pt, pt, color, 5) self.dirty = True self.prev_pt = pt self.show() # palette data from matplotlib/_cm.py _jet_data = {'red': ((0., 0, 0), (0.35, 0, 0), (0.66, 1, 1), (0.89,1, 1), (1, 0.5, 0.5)), 'green': ((0., 0, 0), (0.125,0, 0), (0.375,1, 1), (0.64,1, 1), (0.91,0,0), (1, 0, 0)), 'blue': ((0., 0.5, 0.5), (0.11, 1, 1), (0.34, 1, 1), (0.65,0, 0), (1, 0, 0))} cmap_data = { 'jet' : _jet_data } def make_cmap(name, n=256): data = cmap_data[name] xs = np.linspace(0.0, 1.0, n) channels = [] eps = 1e-6 for ch_name in ['blue', 'green', 'red']: ch_data = data[ch_name] xp, yp = [], [] for x, y1, y2 in ch_data: xp += [x, x+eps] yp += [y1, y2] ch = np.interp(xs, xp, yp) channels.append(ch) return np.uint8(np.array(channels).T*255) def nothing(*arg, **kw): pass def clock(): return cv.getTickCount() / cv.getTickFrequency() @contextmanager def Timer(msg): print msg, '...', start = clock() try: yield finally: print "%.2f ms" % ((clock()-start)*1000) class StatValue: def __init__(self, smooth_coef = 0.5): self.value = None self.smooth_coef = smooth_coef def update(self, v): if self.value is None: self.value = v else: c = self.smooth_coef self.value = c * self.value + (1.0-c) * v class RectSelector: def __init__(self, win, callback): self.win = win self.callback = callback cv.setMouseCallback(win, self.onmouse) self.drag_start = None self.drag_rect = None def onmouse(self, event, x, y, flags, param): x, y = np.int16([x, y]) # BUG if event == cv.EVENT_LBUTTONDOWN: self.drag_start = (x, y) if self.drag_start: if flags & cv.EVENT_FLAG_LBUTTON: xo, yo = self.drag_start x0, y0 = np.minimum([xo, yo], [x, y]) x1, y1 = np.maximum([xo, yo], [x, y]) self.drag_rect = None if x1-x0 > 0 and y1-y0 > 0: self.drag_rect = (x0, y0, x1, y1) else: rect = self.drag_rect self.drag_start = None self.drag_rect = None if rect: self.callback(rect) def draw(self, vis): if not self.drag_rect: return False x0, y0, x1, y1 = self.drag_rect cv.rectangle(vis, (x0, y0), (x1, y1), (0, 255, 0), 2) return True @property def dragging(self): return self.drag_rect is not None 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): '''Make a grid from images. w -- number of grid columns imgs -- images (must have same size and format) ''' 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)) def getsize(img): h, w = img.shape[:2] return w, h def mdot(*args): return reduce(np.dot, args) def draw_keypoints(vis, keypoints, color = (0, 255, 255)): for kp in keypoints: x, y = kp.pt cv.circle(vis, (int(x), int(y)), 2, color)