shade.py

def shade(points, width=1280, height=1024):
    
    max_x = np.max(points[:, 0])
    max_y = np.max(points[:, 1])
    min_x = np.min(points[:, 0])
    min_y = np.min(points[:, 1])
    
    bin_width = (max_x - min_x) / width
    bin_height = (max_y - min_y) / height
    
    aggs = np.zeros((width, height), dtype=np.uint64)

    data_idx = 0
    max_data_idx = points.shape[0]
    
    while data_idx < max_data_idx:
        x, y = points[data_idx]
        res_x = x / bin_width
        res_y = y / bin_height
        aggs[int(res_x), int(res_y)] += 1
        data_idx += 1
                
    aggs = np.log(aggs)

    
    normed_aggs = aggs / np.max(aggs)    
    return normed_aggs
  
from PIL import Image
img = shade(big_array_of_points)

from matplotlib.cm import get_cmap
colormap = get_cmap('Blues')
Image.fromarray((colormap(img, alpha=1.0) * 255).astype(np.uint8), mode='RGBA')