from PIL import Image
from django.db.models.fields.files import ImageField, ImageFieldFile
from django.core.files.base import ContentFile
import os
import math
import re
import colorsys
try:
from cStringIO import StringIO
except ImportError:
from StringIO import StringIO
class PushPinImageFieldFile(ImageFieldFile):
def hex_to_rgb(self, value):
value = value.lstrip('#')
lv = len(value)
return tuple(int(value[i:i+lv/3], 16) for i in range(0, lv, lv/3))
def max_size(self, width, height):
ratio = float(width) / height
if width > self.field.max_width:
width = self.field.max_width
height = int(math.floor(width / ratio))
if height > self.field.max_height:
height = self.field.max_height
width = int(math.floor(height * ratio))
return width, height
def crop_to_fixed(self, img, width, height):
"""
Returns a scaled down and cropped version of the image based on the provided size values.
"""
ratio = float(img.size[0]) / img.size[1]
w = img.size[0]
h = img.size[1]
if (float(w) / width) >= (float(h) / height):
new_h = height
new_w = int(round(height * ratio))
else:
new_w = width
new_h = int(round(width / ratio))
img = img.resize((new_w, new_h), Image.ANTIALIAS)
if (new_w, new_h) != (width, height): # crop needed
if new_w > width:
start_x = int(round(float(new_w - width) / 2))
img = img.crop((start_x, 0, start_x + width, new_h))
elif new_w < width:
img = img.resize((width, new_h), Image.ANTIALIAS)
if new_h > height:
start_y = int(round(float(new_h - height) / 2))
img = img.crop((0, start_y, new_w, start_y + height))
elif new_h < height:
img = img.resize((new_w, height), Image.ANTIALIAS)
return img
def save(self, name, content, save=True):
push_pin_im = Image.open(self.field.push_pin_path)
new_content = StringIO()
content.file.seek(0)
in_image = Image.open(content.file)
# if fixed size given, max will be ignored
if self.field.fixed_width > 0 and self.field.fixed_height > 0:
in_width, in_height = self.field.fixed_width, self.field.fixed_height
else: # get adjusted height and width values
in_width, in_height = self.max_size(in_image.size[0], in_image.size[1])
# adjust further based on borders and stroke
new_in_height = in_height - (self.field.border[0] * 2)
new_in_width = in_width - (self.field.border[0] * 2)
# scale or crop the input image
if self.field.fixed_width or self.field.fixed_height:
scaled_in_image = self.crop_to_fixed(in_image, new_in_width, new_in_height)
else:
scaled_in_image = in_image.resize((new_in_width, new_in_height), Image.ANTIALIAS)
new_im = Image.new('RGB', (in_width, in_height))
# outer stroke
if self.field.outer_border_stroke[0]:
new_im.paste(self.hex_to_rgb(self.field.outer_border_stroke[1]), (0, 0, in_width, in_height))
# the main border
if self.field.border[0]:
new_im.paste(self.hex_to_rgb(self.field.border[1]), (self.field.outer_border_stroke[0], self.field.outer_border_stroke[0],
in_width - self.field.outer_border_stroke[0],
in_height - self.field.outer_border_stroke[0]
))
offset_x = float(in_width - new_in_width) / 2
offset_y = float(in_height - new_in_height) / 2
more_offset_x = 0
if offset_x % 1:
more_offset_x = 1
more_offset_y = 0
if offset_y % 1:
more_offset_y = 1
offset_x = int(math.floor(offset_x))
offset_y = int(math.floor(offset_y))
# inner stroke
if self.field.inner_border_stroke[0]:
new_im.paste(self.hex_to_rgb(self.field.inner_border_stroke[1]), (
offset_x - self.field.inner_border_stroke[0],
offset_y - self.field.inner_border_stroke[0],
in_width - (offset_x + more_offset_x) + self.field.inner_border_stroke[0],
in_height - (offset_y + more_offset_y) + self.field.inner_border_stroke[0]
))
# paste the scaled-down and centered input image
new_im.paste(scaled_in_image, (
offset_x,
offset_y,
offset_x + new_in_width,
offset_y + new_in_height
))
# colorize the push pin
push_pin_im = push_pin_im.convert('RGBA')
pixdata = push_pin_im.load()
rgb_push_pin = self.hex_to_rgb(self.field.push_pin_color)
push_pin_hsv = colorsys.rgb_to_hsv(float(rgb_push_pin[0])/255, float(rgb_push_pin[1])/255,
float(rgb_push_pin[2])/255)
push_pin_hue = push_pin_hsv[0]
push_pin_s = push_pin_hsv[1]
highest_s = list(colorsys.rgb_to_hsv(float(pixdata[16, 20][0])/255, float(pixdata[16, 20][1])/255,
float(pixdata[16, 20][2])/255))[1]
s_offset = push_pin_s - highest_s
for y in xrange(push_pin_im.size[1]):
for x in xrange(push_pin_im.size[0]):
hsv = list(colorsys.rgb_to_hsv(float(pixdata[x, y][0])/255, float(pixdata[x, y][1])/255,
float(pixdata[x, y][2])/255))
if hsv[0]>0:
hsv[0] = push_pin_hue
hsv[1] += s_offset
new_rgb = colorsys.hsv_to_rgb(hsv[0], hsv[1], hsv[2])
pixdata[x, y] = (int(round(new_rgb[0] * 255)), int(round(new_rgb[1] * 255)), int(round(new_rgb[2] * 255)), pixdata[x, y][3])
# paste in the push pin
pin_x = int(round(float(in_width - push_pin_im.size[1]) / 2)) + 8
new_im.paste(push_pin_im, (
pin_x,
1,
pin_x + push_pin_im.size[0],
1 + push_pin_im.size[1]
), push_pin_im)
new_im.save(new_content, format=self.field.format, quality=100)
new_content = ContentFile(new_content.getvalue())
super(PushPinImageFieldFile, self).save(name, new_content, save)
class PushPinImageField(ImageField):
attr_class = PushPinImageFieldFile
@staticmethod
def is_valid_hex_color(value):
if not value.startswith('#') or len(value) != 7 or not re.match('^[A-F0-9]*$', value[1:7].upper()):
return False
else:
return True
def check_color(self, value, field):
if not PushPinImageField.is_valid_hex_color(value):
raise ValueError('The color value for the %s field must contain a valid 6 digit hex color value' \
' and must start with a hash(#) character. Short-hand notation (e.g. #FFF) is' \
' not acceptable.' % field)
def __init__(self, push_pin_path, max_width=150, max_height=100, fixed_width=0, fixed_height=0,
push_pin_color='#ffff33', format='PNG', border=(0, '#ffffff'), inner_border_stroke=(0,'#000000'),
outer_border_stroke=(0, '#000000'), *args, **kwargs):
self.check_color(push_pin_color, 'push_pin_color')
self.check_color(border[1], 'border')
self.check_color(inner_border_stroke[1], 'inner_border_stroke')
self.check_color(outer_border_stroke[1], 'outer_border_stroke')
if inner_border_stroke[0] + outer_border_stroke[0] > border[0]:
raise ValueError('The sum of the sizes of the innner_border_stroke and outer_border_stroke' \
' cannot exceed the size of the border.')
self.push_pin_path = push_pin_path
self.max_width = max_width
self.max_height = max_height
self.fixed_width = fixed_width
self.fixed_height = fixed_height
self.push_pin_color = push_pin_color
self.format = format
self.border = border
self.inner_border_stroke = inner_border_stroke
self.outer_border_stroke = outer_border_stroke
super(PushPinImageField, self).__init__(*args, **kwargs)