#!/usr/bin/env python # paultaney ta yahoo.com # with kind assistance from Chris.Barker ta NOAA.gov # and St\xe9fan on the scipy list (test7) import wx import numpy as np YOU_HAVE_AN_IMAGE = 0 if YOU_HAVE_AN_IMAGE: path = "8bitchart01_small.tiff" # put its name here image = wx.Image(path, wx.BITMAP_TYPE_ANY) w, h = image.GetWidth(), image.GetHeight() # Rappin page 362, Smart page 285 a = np.fromstring(image.GetData(), np.uint8) a.reshape(w, h, 3) else: # for testing: # gen test data (minus the commas) # data = np.random.randint(0,255,(5,5,3)) # print "d = np.array(%s, np.uint8)" % (data) a = np.array( # x y [[[ 64, 237, 108], # [0, 0] [185, 240, 68], # [0, 1] test five [ 17, 116, 55], # [0, 2] is said to be blue (THIRD) XXX [107, 11, 185], # [0, 3] is blue (SIXTH) [154, 30, 52]], # [0, 4] [[251, 73, 150], # [1, 0] [ 47, 225, 97], # [1, 1] [101, 91, 251], # [1, 2] is blue (FOURTH) [ 61, 23, 79], # [1, 3] [161, 22, 165]], # [1, 4] [[ 4, 162, 188], # [2, 0] [ 25, 131, 211], # [2, 1] is blue (SECOND) [162, 112, 177], # [2, 2] [169, 83, 214], # [2, 3] is blue (not reported) [254, 139, 95]], # [2, 4] [[ 2, 88, 216], # [3, 0] is blue (FIRST) [230, 63, 192], # [3, 1] [ 71, 78, 50], # [3, 2] is said to be blue (FIFTH) [113, 151, 150], # [3, 3] is said to be blue (SEVENTH) [104, 65, 250]], # [3, 4] is blue (EIGHTH) [[ 6, 191, 220], # [4, 0] is blue (not reported) [ 38, 141, 4], [245, 41, 23], [ 23, 127, 183], # [4, 3] is blue (not reported) [165, 24, 5]]], np.uint8) DIM = (5, 5) def test1(a): red, grn, blu = a[0,0] print "r=%r, g=%r, b=%r" % (red, grn, blu) # prints r=64, g=237, b=108 red, grn, blu = a[4, 4] print "r=%r, g=%r, b=%r" % (red, grn, blu) # prints r=165, g=24, b=5 def test2(a): # this is a threshold filter rmin, rmax, gmin, gmax, bmin, bmax = 0,178, 0,178, 178,255 very_blue_pixels = [] w = DIM[0] x = y = 0 # searches rows first (x is turning faster, so...) for xyslice in a: for xslice in xyslice: if 0: print "x=%r, y=%r, type(xslice)= %r" % (x, y, type(xslice)) if 0: print "a[x=%i, y=%i] = %r" % (x, y, a[x,y]) red, grn, blu = xslice if (rmin <= red <= rmax) and \ (gmin <= grn <= gmax) and \ (bmin <= blu <= bmax): if 1: print "a very blue pixel at x=%i, y=%i, rgb=%r" % (x, y, xslice) very_blue_pixels.append((x,y)) x += 1 if x==w: x=0 # ugly y += 1 print "test2: very_blue_pixels=%r" % (very_blue_pixels) #a very blue pixel at x=3, y=0, rgb=array([107, 11, 185], dtype=uint8) #a very blue pixel at x=2, y=1, rgb=array([101, 91, 251], dtype=uint8) #a very blue pixel at x=0, y=2, rgb=array([ 4, 162, 188], dtype=uint8) #a very blue pixel at x=1, y=2, rgb=array([ 25, 131, 211], dtype=uint8) #a very blue pixel at x=3, y=2, rgb=array([169, 83, 214], dtype=uint8) #a very blue pixel at x=0, y=3, rgb=array([ 2, 88, 216], dtype=uint8) #a very blue pixel at x=4, y=3, rgb=array([104, 65, 250], dtype=uint8) #a very blue pixel at x=3, y=4, rgb=array([ 23, 127, 183], dtype=uint8) #test2: very_blue_pixels=[(3, 0), (2, 1), (0, 2), (1, 2), (3, 2), (0, 3), (4, 3), (3, 4)] def test3(a, THRESH): # for my dataset I can optimize the above loop like this # at the cost of getting less output since the THRESHOLD is only one number # very_blue_pixels = [] w = DIM[0] x = y = 0 for xyslice in a: for xslice in xyslice: red, grn, blu = xslice if (red <= THRESH) and (grn <= THRESH) and (THRESH <= blu): very_blue_pixels.append((x, y)) if 1: print "I see blue a[x=%i, y=%i] pixel = %r" % (x, y, xslice) x += 1 if x==w: x=0 y += 1 print "test3: very_blue_pixels=%r" % (very_blue_pixels) #I see blue a[x=3, y=0] pixel = array([107, 11, 185], dtype=uint8) #I see blue a[x=2, y=1] pixel = array([101, 91, 251], dtype=uint8) #I see blue a[x=0, y=2] pixel = array([ 4, 162, 188], dtype=uint8) #I see blue a[x=1, y=2] pixel = array([ 25, 131, 211], dtype=uint8) #I see blue a[x=3, y=2] pixel = array([169, 83, 214], dtype=uint8) #I see blue a[x=0, y=3] pixel = array([ 2, 88, 216], dtype=uint8) #I see blue a[x=4, y=3] pixel = array([104, 65, 250], dtype=uint8) #I see blue a[x=3, y=4] pixel = array([ 23, 127, 183], dtype=uint8) #test3: very_blue_pixels=[(3, 0), (2, 1), (0, 2), (1, 2), (3, 2), (0, 3), (4, 3), (3, 4)] def test4(a): RED, GRN, BLU = 0, 1, 2 rmin, rmax, gmin, gmax, bmin, bmax = 0,178, 0,178, 100,255 line_pix = ((rmin <= a[:, :, RED] <= rmax) & (gmin <= a[:, :, GRN] <= gmax) & (bmin <= a[:, :, BLU] <= bmax)) print "test4: line_pix = %r" % (line_pix) # ValueError: The truth value of an array with more than # one element is ambiguous. Use a.any() or a.all() def test5(a, THRESH): RED, GRN, BLU = 0, 1, 2 line_pix = ((a[:, :, RED] <= THRESH) & (a[:, :, GRN] <= THRESH) & (a[:, :, BLU] >= THRESH)) print "test5: line_pix = %r" % (line_pix) return line_pix #test5: line_pix = array( # x=0 1 2 3 4 # y=0 [[False, False, False, True, False], # [3, 0] is blue # 1 [False, False, True, False, False], # [2, 1] is blue # 2 [ True, True, False, True, False], # [0, 2] xxx, [1, 2] is blue, [3, 2] xxx # 3 [ True, False, False, True, False], # [0, 3] is blue, [4, 3] # 4 [False, False, False, True, False]]) # [3, 4] is blue # cf test3: [(3, 0), (2, 1), (0, 2), (1, 2), (3, 2), (0, 3), (4, 3), (3, 4)] def test6(a, rmax, gmax, bmin): RED, GRN, BLU = 0, 1, 2 line_pix = ((a[:, :, RED] <= rmax) & (a[:, :, GRN] <= gmax) & (a[:, :, BLU] >= bmin)) print "test6: line_pix = %r" % (line_pix) def dump_bool_array(b): very_blue_pixels = [] w = DIM[0] x = y = 0 for xyslice in b: for bool in xyslice: if bool: very_blue_pixels.append((x, y)) x += 1 if x==w: x=0 y += 1 print "dump_bool_array=%r" % (very_blue_pixels) # [(3, 0), (2, 1), (0, 2), (1, 2), (3, 2), (0, 3), (4, 3), (3, 4)] # BINGO! def test7(a, fact): RED, GRN, BLU = 0, 1, 2 bluemask = (a[...,BLU] > fact*a[...,GRN]) & (a[...,2] > fact*a[...,RED]) b = a[bluemask, :] print "test 7 with factor=%f" % fact return b # test1(a) # passed # test2(a) # passed # test3(a, 178) # passed # test4(a) # FAILS # dump_bool_array(test5(a, 178)) # ??? # test6(a, 178, 178, 100) # ??? print test7(a, 1.25) print test7(a, 1.4) #