python, pillow, pil, image processing demo

python_pil_demo_study.py

import os
import numpy as np
import cv2
from PIL import Image
from PIL import ImageDraw
from PIL import ImageFilter

'''
ref : http://pillow.readthedocs.io/en/3.4.x/index.html
ref : basic : https://www.youtube.com/watch?v=Fd_0ns8bmCY
video tutorial : https://www.youtube.com/watch?v=j6tXKS2Pl8Q and more...

'''

demo_python = '/Users/mulder/Desktop/demo-python.png'
demo_file = '/Users/mulder/Desktop/demo.png'
demo2_file = '/Users/mulder/Desktop/demo2.png'

def demo_new():
    size = width, height = 320, 240
    #image = Image.new("RGB", size, "rgb(100,200,220)")
    image = Image.new("RGB", size, "hsl(0, 100%, 20%)")
    image.show()
    del image

def demo_getpixel():
    image = Image.open(demo_file)
    size = width, height = image.size
    coordinate = x, y = 180, 69
    print image.getpixel( coordinate )
    # Returns:  The pixel value. If the image is a multi-layer image, this method returns a tuple.  # (R,G,B,A)
    image.show();
    del image

def demo_blend():
    image1 = Image.open(demo_file)
    image1_size = width, height = image1.size
    image2 = Image.open(demo2_file).resize(image1_size, Image.ANTIALIAS)

    Image.blend(image1, image2, 0.5).show()

    del image1, image2

def demo_composite():
    image1 = Image.open(demo_file)
    image1_size = width, height = image1.size
    image2 = Image.open(demo2_file).resize(image1_size, Image.ANTIALIAS)

    Image.composite(image1, image2, image1).show()

    del image1, image2

def demo_convert():
    image = Image.open(demo_file)
    image.convert("L").show();
    del image

def demo_crop():
    image = Image.open(demo_file)
    image.crop( (10, 10, 400, 200) ).show();
    del image

def demo_filter():
    image = Image.open(demo_file)
    image.filter( ImageFilter.BLUR  ).show();
    raw_input()
    image.filter( ImageFilter.CONTOUR  ).show();
    raw_input()
    image.filter( ImageFilter.EDGE_ENHANCE ).show();
    raw_input()
    image.filter( ImageFilter.EDGE_ENHANCE_MORE ).show();
    raw_input()
    image.filter( ImageFilter.EMBOSS ).show();
    raw_input()
    image.filter( ImageFilter.FIND_EDGES ).show();
    raw_input()
    image.filter( ImageFilter.SMOOTH ).show();
    raw_input()
    image.filter( ImageFilter.SMOOTH_MORE ).show();
    raw_input()
    image.filter( ImageFilter.SHARPEN ).show();
    del image



def demo_getcolors():
    image = Image.open(demo_python)
    size = width, height = image.size
    image.show()
    print image.getcolors(width * height)
    # Returns:  An unsorted list of (count, pixel) values.
    del image


def demo_getdata():
    image = Image.open(demo_python)
    size = width, height = image.size
    image.show()
    print list(image.getdata())
    # A sequence-like object.
    del image

def demo_paste():
    image = Image.open(demo_python)
    size = width, height = image.size
    image.paste('blue', (10,10, 50, 200))
    image.show()
    #
    image1 = Image.open(demo_file)
    image2 = Image.open(demo2_file).crop( (0, 0, 400, 200) )
    image1.paste(image2, (200, 200, 600, 400))
    image1.show()
    del image, image1, image2

def demo_rotate_and_putdata_and_save():
    image = Image.open(demo_python)
    size = width, height = image.size

    rotated_img = image.rotate(56)
    rotated_img.show()

    color_to_find = (0, 0, 0, 0)
    color_to_replace = (255, 255, 255, 255)

    new_image_data = []
    for color in list(rotated_img.getdata()):
      if (color == color_to_find):
        new_image_data += [ color_to_replace ]
      else:
        new_image_data += [ color ]

    rotated_img.putdata( new_image_data )
    rotated_img.show()
    rotated_img.save('rotated_img.png')
    del image, rotated_img


def demo_putpixel_basic():
    image = Image.open(demo_python)
    size = width, height = image.size

    x = 100
    for y in range(100):
      image.putpixel( (x,y), (0,0,0, 255) )

    image.show()
    del image

def demo_get_pixel_object():
    image = Image.open(demo_python)
    size = width, height = image.size

    pixel_access_object = image.load()

    y=100
    for x in range(width):
      print str(x)+":"+str(y)+"=>", pixel_access_object[x,y]
    del image

def demo_transpose():
    image = Image.open(demo_python)
    size = width, height = image.size

    tpImage = image.transpose(Image.FLIP_LEFT_RIGHT)
    # FLIP_TOP_BOTTOM,ROTATE_90,ROTATE_180,ROTATE_270,TRANSPOSE     
    tpImage.show()
    del image, tpImage

def demo_load_split_merge_mode():
    image = Image.open(demo_python)
    size = width, height = image.size
    print image.mode

    image.load()

    r,g,b, a = image.split()
    #image = Image.merge("RGB", (r,g,b))
    image = Image.merge("RGB", (b,g,r))
    print image.mode
    
    #for color in image.getdata():
    #  print color

    image.show()

    del image

def demo_print_image_fnames_in_dir():
    for f in os.listdir("/Users/mulder/Desktop"):
      if (f.endswith(".png")):
        #i = Image.open(f)
        fn, ext = os.path.splitext(f)
        print('png => {} : {}'.format(fn, ext))
        # print like : png => spine-8point-mark-01 : .png

def demo_paste_and_make_multi_pic():
    original = Image.open(demo_python)
    original.show('original');
    x_size, y_size = original.size
    x_half, y_half = x_size/2, y_size/2
    half = original.resize((x_half, y_half))
    x_double, y_double = x_size*2, y_size*2
    double = Image.new("RGB", (x_double, y_double))
    for x in range(4):
        for y in range(4):
            box = (x*x_half, y*y_half, (x+1)*x_half, (y+1)*y_half)
            double.paste(half, box)
    double.show('double');
    del original, double



def demo_draw_frame():
    BORDER = 10
    GRAY = (128,128,128)
    pic = Image.open(demo_python)
    x_size, y_size = pic.size
    draw = ImageDraw.Draw(pic)

    draw.rectangle((0,0, x_size, BORDER), fill=GRAY)
    draw.rectangle((0,0, BORDER, y_size), fill=GRAY)
    draw.rectangle((0,y_size-BORDER, x_size, y_size), fill=GRAY)
    draw.rectangle((x_size-BORDER, 0, x_size, y_size), fill=GRAY)

    pic.show('framed');

    del pic


def demo_split_and_merge():
    R, G, B, = 0, 1, 2
    SCALE = 0.5
    def decrease(x): return x * SCALE

    pic = Image.open(demo_python)
    pic.load()
    bands = pic.split()
    bands = (bands[R].point(decrease), bands[G], bands[B])
    more_red = Image.merge("RGB", bands)
    more_red.show('more-red')

    del pic, more_red

def demo_blend_paste_image_overlap():
    def get(f):
      pic = Image.open(f)
      x_size, y_size = pic.size
      return (pic, x_size, y_size)

    BLEND = 0.8
    major_name, highlight_name = demo_file, demo_python
    major, major_x, major_y = get(major_name)
    highlight, hl_x, hl_y = get(highlight_name)

    box = (50, 50, 50+hl_x, 50+hl_y)

    middle = major.crop(box)
    middle = Image.blend(middle, highlight, BLEND)
    major.paste(middle, box)
    major.show()

    del major, highlight


def demo_img_init_gradation_effect():
    img = Image.new("RGB", (640,400), (0,0,255))
    for x in xrange(640):
        for y in xrange(400):
            img.putpixel( (x,y), (x/3,(x+y)/6, y/2) )
    img.show()
    del img

def demo_last():
    img = Image.open(demo_file)
    for x in xrange(img.size[0]):
        for y in xrange(img.size[1]):
            r,g,b, a = img.getpixel((x,y))
            img.putpixel( (x,y), (b,g,r) )
    img.show()
    del img


demo_last()