palette.py 文件源码

def find_dominant_colors(image):
    """Cluster the colors of the image in CLUSTER_NUMBER of clusters. Returns
    an array of dominant colors reverse sorted by cluster size.
    """

    array = img_as_float(fromimage(image))

    # Reshape from MxNx4 to Mx4 array
    array = array.reshape(scipy.product(array.shape[:2]), array.shape[2])

    # Remove transparent pixels if any (channel 4 is alpha)
    if array.shape[-1] > 3:
        array = array[array[:, 3] == 1]

    # Finding centroids (centroids are colors)
    centroids, _ = kmeans(array, CLUSTER_NUMBER)

    # Allocate pixel to a centroid cluster
    observations, _ = vq(array, centroids)

    # Calculate the number of pixels in a cluster
    histogram, _ = scipy.histogram(observations, len(centroids))

    # Sort centroids by number of pixels in their cluster
    sorted_centroids = sorted(zip(centroids, histogram),
                              key=lambda x: x[1],
                              reverse=True)

    sorted_colors = tuple((couple[0] for couple in sorted_centroids))

    return sorted_colors