from PIL import Image

from commons import clear

def edge_detection(image):
    image_l = image.load()
    new_image = Image.new('L', image.size)
    new_image_l = new_image.load()
    clear()
    print "edge detection"
    for x in range(2, image.size[0] - 2):
        for y in range(2, image.size[1] - 2):
            pix = (sum([sum([
                image_l[a, b] 
                    for b in range(y - 2, y + 3)]) 
                    for a in range(x - 2, x + 3)])
                - (25 * image_l[x, y]))
            if pix > 255:
                pix = 255
            if pix < 0:
                pix = 0 
            new_image_l[x, y] = pix
    return new_image
	
def peaks(image):
    image_l = image.load()
    new_image = Image.new('L', image.size)
    new_image_l = new_image.load()
    clear()
    print "peak extraction"
    for x in range(2, image.size[0] - 2):
        for y in range(2, image.size[1] - 2):
            pix = (sum([sum([
                - image_l[a, b] 
                    for b in range(y - 2, y + 3)]) 
                    for a in range(x - 2, x + 3)])
                + (16 * image_l[x, y]))
            if pix > 255:
                pix = 255
            if pix < 0:
                pix = 0 
            new_image_l[x, y] = pix
    return new_image

def high_pass(image, height):
    image_l = image.load()
    new_image = Image.new('L', image.size)
    new_image_l = new_image.load()
    clear()
    print "high pass filter"
    for x in xrange(image.size[0]):
        for y in xrange(image.size[1]):
            if image_l[x, y] < height:
                new_image_l[x, y] = 0
            else:
                new_image_l[x, y] = image_l[x, y]

    return new_image