def create_shape_image_sample(shape, sample_width=256, sample_height=256):
""" Return a centered image sample of the shape, or None if a centered
box intersects the shape edge """
from shapes.models import ShapeImageSample
from common.wavelets import compute_wavelet_feature_vector
if ShapeImageSample.objects.filter(shape=shape).exists():
return
image = open_image(shape.photo.image_2048)
image_width, image_height = image.size
triangles = parse_triangles(shape.triangles)
vertices = [(x * image_width, y * image_height)
for (x, y) in parse_vertices(shape.vertices)]
b = bbox_vertices(vertices)
# make sure box is big enough
if b[2] - b[0] < sample_width or b[3] - b[1] < sample_height:
return None
# try random boxes
filled = False
for iters in xrange(1000):
x = int(random.uniform(b[0] + sample_width / 2, b[2] - sample_width / 2))
y = int(random.uniform(b[1] + sample_height / 2, b[3] - sample_height / 2))
box = (x - sample_width / 2, y - sample_height / 2,
x + sample_width / 2, y + sample_height / 2)
box = [int(f) for f in box]
# make sure box is filled entirely
poly = Image.new(mode='1', size=(box[2] - box[0], box[3] - box[1]), color=0)
draw = ImageDraw.Draw(poly)
vertices_shifted = [(x - box[0], y - box[1]) for (x, y) in vertices]
for tri in triangles:
points = [vertices_shifted[tri[t]] for t in (0, 1, 2)]
draw.polygon(points, fill=1)
del draw
filled = True
for p in poly.getdata():
if p != 1:
filled = False
break
if filled:
break
if not filled:
return None
# create sample
sample, created = ShapeImageSample.objects.get_or_create(
shape=shape, defaults={'bbox': json.dumps(box)})
if created:
sample_image = image.crop(box)
sample.feature_vector = \
compute_wavelet_feature_vector(sample_image)
save_obj_attr_image(
sample, attr='image', img=sample_image, format='jpg', save=True)
return sample
def compute_features(wavelet, img):
return compute_wavelet_feature_vector(Image.open(img), wavelet=wavelet)
def compute_features(wavelet, img):
return compute_wavelet_feature_vector(Image.open(img), wavelet=wavelet)
