|
1
|
|
|
""" |
|
2
|
|
|
This module implement a Thumbnail filter. |
|
3
|
|
|
""" |
|
4
|
|
|
from PIL import Image |
|
5
|
|
|
from .interface import ImagineFilterInterface |
|
6
|
|
|
|
|
7
|
|
|
|
|
8
|
|
|
class ThumbnailFilter(ImagineFilterInterface): |
|
9
|
|
|
""" |
|
10
|
|
|
Thumbnail filter |
|
11
|
|
|
""" |
|
12
|
|
|
modes = ['inset', 'outbound'] |
|
13
|
|
|
mode = 'inset' |
|
14
|
|
|
width = 0 |
|
15
|
|
|
height = 0 |
|
16
|
|
|
|
|
17
|
|
|
def __init__(self, **kwargs): |
|
18
|
|
|
""" |
|
19
|
|
|
Filter initialization |
|
20
|
|
|
:param kwargs: parameters |
|
21
|
|
|
""" |
|
22
|
|
|
if 'mode' in kwargs and kwargs['mode'] in self.modes: |
|
23
|
|
|
self.mode = kwargs.pop('mode') |
|
24
|
|
|
|
|
25
|
|
|
if 'size' in kwargs and isinstance(kwargs['size'], list) and len(kwargs['size']) == 2: |
|
26
|
|
|
size = kwargs.pop('size', [0, 0]) |
|
27
|
|
|
self.width = size[0] |
|
28
|
|
|
self.height = size[1] |
|
29
|
|
|
else: |
|
30
|
|
|
raise ValueError('Thumbnail size is not set.') |
|
31
|
|
|
|
|
32
|
|
|
def apply(self, resource): |
|
33
|
|
|
""" |
|
34
|
|
|
Apply filter to resource |
|
35
|
|
|
:param resource: Image |
|
36
|
|
|
:return: Image |
|
37
|
|
|
""" |
|
38
|
|
|
if not isinstance(resource, Image.Image): |
|
39
|
|
|
raise ValueError('Unknown resource format') |
|
40
|
|
|
|
|
41
|
|
|
original_width, original_height = resource.size |
|
42
|
|
|
|
|
43
|
|
|
resource_format = resource.format |
|
44
|
|
|
|
|
45
|
|
|
if self.mode == 'outbound': |
|
46
|
|
|
target_width, target_height = self.outbound_sizes(original_width, original_height, self.width, self.height) |
|
47
|
|
|
resource = resource.resize((target_width, target_height), Image.ANTIALIAS) |
|
48
|
|
|
|
|
49
|
|
|
crop_sizes = self.crop_sizes(target_width, target_height, self.width, self.height) |
|
50
|
|
|
resource = resource.crop(crop_sizes) |
|
51
|
|
|
else: |
|
52
|
|
|
target_width, target_height = self.inset_sizes(original_width, original_height, self.width, self.height) |
|
53
|
|
|
resource = resource.resize((target_width, target_height), Image.ANTIALIAS) |
|
54
|
|
|
|
|
55
|
|
|
resource.format = resource_format |
|
56
|
|
|
|
|
57
|
|
|
return resource |
|
58
|
|
|
|
|
59
|
|
|
@classmethod |
|
60
|
|
|
def inset_sizes(cls, original_width, original_height, target_width, target_height): |
|
61
|
|
|
""" |
|
62
|
|
|
Calculate new image sizes for inset mode |
|
63
|
|
|
:param original_width: int |
|
64
|
|
|
:param original_height: int |
|
65
|
|
|
:param target_width: int |
|
66
|
|
|
:param target_height: int |
|
67
|
|
|
:return: tuple(int, int) |
|
68
|
|
|
""" |
|
69
|
|
|
if target_width >= original_width and target_height >= original_height: |
|
70
|
|
|
target_width = float(original_width) |
|
71
|
|
|
target_height = original_height |
|
72
|
|
|
|
|
73
|
|
|
elif target_width <= original_width and target_height >= original_height: |
|
74
|
|
|
k = original_width / float(target_width) |
|
75
|
|
|
target_height = int(original_height / k) |
|
76
|
|
|
|
|
77
|
|
|
elif target_width >= original_width and target_height <= original_height: |
|
78
|
|
|
k = original_height / float(target_height) |
|
79
|
|
|
target_width = int(original_width / k) |
|
80
|
|
|
|
|
81
|
|
|
elif target_width < original_width and target_height < original_height: |
|
82
|
|
|
k = original_width / float(original_height) |
|
83
|
|
|
k_w = original_width / float(target_width) |
|
84
|
|
|
k_h = original_height / float(target_height) |
|
85
|
|
|
|
|
86
|
|
|
if k_w >= k_h: |
|
87
|
|
|
target_height = int(target_width / k) |
|
88
|
|
|
else: |
|
89
|
|
|
target_width = int(target_height * k) |
|
90
|
|
|
|
|
91
|
|
|
return target_width, target_height |
|
92
|
|
|
|
|
93
|
|
|
@classmethod |
|
94
|
|
|
def outbound_sizes(cls, original_width, original_height, target_width, target_height): |
|
95
|
|
|
""" |
|
96
|
|
|
Calculate new image sizes for outbound mode |
|
97
|
|
|
:param original_width: int |
|
98
|
|
|
:param original_height: int |
|
99
|
|
|
:param target_width: int |
|
100
|
|
|
:param target_height: int |
|
101
|
|
|
:return: tuple(int, int) |
|
102
|
|
|
""" |
|
103
|
|
|
if target_width <= original_width and target_height <= original_height: |
|
104
|
|
|
k = original_width / float(original_height) |
|
105
|
|
|
k_w = original_width / float(target_width) |
|
106
|
|
|
k_h = original_height / float(target_height) |
|
107
|
|
|
|
|
108
|
|
|
if k_w > k_h: |
|
109
|
|
|
target_width = int(target_height * k) |
|
110
|
|
|
else: |
|
111
|
|
|
target_height = int(target_width / k) |
|
112
|
|
|
else: |
|
113
|
|
|
target_width = original_width |
|
114
|
|
|
target_height = original_height |
|
115
|
|
|
|
|
116
|
|
|
return target_width, target_height |
|
117
|
|
|
|
|
118
|
|
|
@classmethod |
|
119
|
|
|
def crop_sizes(cls, original_width, original_height, target_width, target_height): |
|
120
|
|
|
""" |
|
121
|
|
|
Calculate crop parameters for outbound mode |
|
122
|
|
|
:param original_width: int |
|
123
|
|
|
:param original_height: int |
|
124
|
|
|
:param target_width: int |
|
125
|
|
|
:param target_height: int |
|
126
|
|
|
:return: tuple(int, int, int, int) |
|
127
|
|
|
""" |
|
128
|
|
|
if target_width < original_width: |
|
129
|
|
|
left = abs(original_width - target_width) / 2 |
|
130
|
|
|
right = left + target_width |
|
131
|
|
|
else: |
|
132
|
|
|
left = 0 |
|
133
|
|
|
right = original_width |
|
134
|
|
|
if target_height < original_height: |
|
135
|
|
|
upper = abs(original_height - target_height) / 2 |
|
136
|
|
|
lower = upper + target_height |
|
137
|
|
|
else: |
|
138
|
|
|
upper = 0 |
|
139
|
|
|
lower = original_height |
|
140
|
|
|
|
|
141
|
|
|
return left, upper, right, lower |
|
142
|
|
|
|
FlaskGuys /
Flask-Imagine
