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for n, factors in usable_factors.iteritems()
for factor in factors
if (factor <= max_vert_cells and
n // factor <= max_hor_cells)]
if not overlap_options:
# We can't stack the image
return convolution(bin_template, bin_image, tollerance=tollerance)
best_overlap = min(overlap_options,
key=lambda x: ((ih // x[0] + th) * (iw // x[1] + tw)))
return overlapped_convolution(bin_template, bin_image,
tollerance=tollerance, splits=best_overlap)"
4257,"def overlapped_convolution(bin_template, bin_image,
tollerance=0.5, splits=(4, 2)):
""""""
As each of these images are hold only binary values, and RFFT2 works on
float64 greyscale values, we can make the convolution more efficient by
breaking the image up into :splits: sectons. Each one of these sections
then has its greyscale value adjusted and then stacked.
We then apply the convolution to this 'stack' of images, and adjust the
resultant position matches.
""""""
th, tw = bin_template.shape
ih, iw = bin_image.shape
hs, ws = splits
h = ih // hs
w = iw // ws
count = numpy.count_nonzero(bin_template)
assert count > 0
assert h >= th
assert w >= tw
yoffset = [(i * h, ((i + 1) * h) + (th - 1)) for i in range(hs)]
xoffset = [(i * w, ((i + 1) * w) + (tw - 1)) for i in range(ws)]
# image_stacks is Origin (x,y), array, z (height in stack)
image_stacks = [((x1, y1), bin_image[y1:y2, x1:x2], float((count + 1) ** (num)))
for num, (x1, x2, y1, y2) in
enumerate((x1, x2, y1, y2) for (x1, x2)
in xoffset for (y1, y2) in yoffset)]
pad_h = max(i.shape[0] for _, i, _ in image_stacks)
pad_w = max(i.shape[1] for _, i, _ in image_stacks)
# rfft metrics must be an even size - why ... maths?
pad_w += pad_w % 2
pad_h += pad_h % 2
overlapped_image = sum_2d_images(pad_bin_image_to_shape(i, (pad_h, pad_w))
* num for _, i, num in image_stacks)
#print ""Overlap splits %r, Image Size (%d,%d),
#Overlapped Size (%d,%d)"" % (splits,iw,ih,pad_w,pad_h)
# Calculate the convolution of the FFT's of the overlapped image & template
convolution_freqs = (rfft2(overlapped_image) *
rfft2(bin_template[::-1, ::-1],
overlapped_image.shape))
# Reverse the FFT to find the result overlapped image
convolution_image = irfft2(convolution_freqs)
# At this point, the maximum point in convolution_image should be the
# bottom right (why?) of the area of greatest match
results = set()
for (x, y), _, num in image_stacks[::-1]:
test = convolution_image / num
filtered = ((test >= (count - tollerance)) &
(test <= (count + tollerance)))
match_points = numpy.transpose(numpy.nonzero(filtered)) # bottom right
for (fy, fx) in match_points:
if fx < (tw - 1) or fy < (th - 1):
continue
results.add((x + fx - (tw - 1), y + fy - (th - 1)))
convolution_image %= num
return list(results)"
4258,"def get_partition_scores(image, min_w=1, min_h=1):
""""""Return list of best to worst binary splits along the x and y axis.
""""""
h, w = image.shape[:2]
if w == 0 or h == 0:
return []
area = h * w
cnz = numpy.count_nonzero
total = cnz(image)
if total == 0 or area == total:
return []
if h < min_h * 2:
y_c = []
else:
y_c = [(-abs((count / ((h - y) * w)) - ((total - count) / (y * w))),
y, 0)
for count, y in ((cnz(image[y:]), y)
for y in range(min_h, image.shape[0] - min_h))]
if w < min_w * 2:
x_c = []
else:
x_c = [(-abs((count / (h * (w - x))) - ((total - count) / (h * x))),
x, 1)
for count, x in ((cnz(image[:, x:]), x)