Файзуллов Айрат Рафагатович 530 группа BmpParser 16640
Вдовин Андрей Алексеевич 325 BmpParser 14971
t1import syst1import sys
2import struct2import struct
33
4def read_bmp(data):4def read_bmp(data):
5    file_length = len(data)5    file_length = len(data)
6    if file_length < 26:6    if file_length < 26:
7        print('Incorrect size')7        print('Incorrect size')
8        return8        return
9    try:9    try:
10        bmp_header = data[:14]10        bmp_header = data[:14]
11        signature, file_size, reserved1, reserved2, pixel_array_offset =11        signature, file_size, reserved1, reserved2, pixel_array_offset =
> struct.unpack('<2sIHHI', bmp_header)> struct.unpack('<2sIHHI', bmp_header)
12    except struct.error:12    except struct.error:
13        print('Incorrect size')13        print('Incorrect size')
14        return14        return
15    if signature != b'BM':15    if signature != b'BM':
16        print('Not a Windows BMP')16        print('Not a Windows BMP')
17        return17        return
18    if file_size != file_length:18    if file_size != file_length:
19        print('Incorrect size')19        print('Incorrect size')
20        return20        return
21    try:21    try:
22        dib_header_size = struct.unpack('<I', data[14:18])[0]22        dib_header_size = struct.unpack('<I', data[14:18])[0]
23    except struct.error:23    except struct.error:
24        print('Incorrect size')24        print('Incorrect size')
25        return25        return
26    valid_dib_sizes = [12, 16, 40, 52, 56, 64, 108, 124]26    valid_dib_sizes = [12, 16, 40, 52, 56, 64, 108, 124]
27    if dib_header_size not in valid_dib_sizes:27    if dib_header_size not in valid_dib_sizes:
28        print('Incorrect header size')28        print('Incorrect header size')
29        return29        return
30    if file_length < 14 + dib_header_size:30    if file_length < 14 + dib_header_size:
31        print('Incorrect size')31        print('Incorrect size')
32        return32        return
33    dib_header = data[14:14 + dib_header_size]33    dib_header = data[14:14 + dib_header_size]
34    if dib_header_size == 12:34    if dib_header_size == 12:
35        try:35        try:
36            _, width, height, planes, bits_per_pixel = struct.unpack('<I36            _, width, height, planes, bits_per_pixel = struct.unpack('<I
>HHHH', dib_header[:12])>HHHH', dib_header[:12])
37            compression = 037            compression = 0
38            pixel_array_size = 038            pixel_array_size = 0
39        except struct.error:39        except struct.error:
40            print('Incorrect size')40            print('Incorrect size')
41            return41            return
42    elif dib_header_size >= 40:42    elif dib_header_size >= 40:
43        try:43        try:
44            unpack_format = '<IiiHHII'44            unpack_format = '<IiiHHII'
45            unpack_size = struct.calcsize(unpack_format)45            unpack_size = struct.calcsize(unpack_format)
46            fields = struct.unpack(unpack_format, dib_header[:unpack_siz46            fields = struct.unpack(unpack_format, dib_header[:unpack_siz
>e])>e])
47            _, width, height, planes, bits_per_pixel, compression, pixel47            _, width, height, planes, bits_per_pixel, compression, pixel
>_array_size = fields>_array_size = fields
48        except struct.error:48        except struct.error:
49            print('Incorrect size')49            print('Incorrect size')
50            return50            return
51    else:51    else:
52        print('Incorrect header size')52        print('Incorrect header size')
53        return53        return
54    if planes != 1:54    if planes != 1:
55        print('Incorrect header size')55        print('Incorrect header size')
56        return56        return
57    abs_width = abs(width)57    abs_width = abs(width)
58    abs_height = abs(height)58    abs_height = abs(height)
59    if bits_per_pixel <= 0:59    if bits_per_pixel <= 0:
60        print('Incorrect header size')60        print('Incorrect header size')
61        return61        return
62    bits_per_row = abs_width * bits_per_pixel62    bits_per_row = abs_width * bits_per_pixel
63    bytes_per_row = (bits_per_row + 7) // 863    bytes_per_row = (bits_per_row + 7) // 8
64    padding = (4 - bytes_per_row % 4) % 464    padding = (4 - bytes_per_row % 4) % 4
65    row_size_padded = bytes_per_row + padding65    row_size_padded = bytes_per_row + padding
66    computed_pixel_array_size = row_size_padded * abs_height66    computed_pixel_array_size = row_size_padded * abs_height
67    if dib_header_size >= 40:67    if dib_header_size >= 40:
68        specified_pixel_array_size = pixel_array_size68        specified_pixel_array_size = pixel_array_size
69    else:69    else:
70        specified_pixel_array_size = 070        specified_pixel_array_size = 0
71    size_matches = False71    size_matches = False
72    padding_size = 072    padding_size = 0
73    if specified_pixel_array_size == 0:73    if specified_pixel_array_size == 0:
74        size_matches = True74        size_matches = True
75    elif specified_pixel_array_size == computed_pixel_array_size:75    elif specified_pixel_array_size == computed_pixel_array_size:
76        size_matches = True76        size_matches = True
77    elif specified_pixel_array_size == computed_pixel_array_size + 2:77    elif specified_pixel_array_size == computed_pixel_array_size + 2:
78        size_matches = True78        size_matches = True
79        padding_size = 279        padding_size = 2
80    else:80    else:
81        size_matches = False81        size_matches = False
82    if not size_matches:82    if not size_matches:
83        print('Incorrect image size')83        print('Incorrect image size')
84        return84        return
85    compression_method = compression if dib_header_size >= 40 else 085    compression_method = compression if dib_header_size >= 40 else 0
86    print(abs_width, abs_height, bits_per_pixel, compression_method, pad86    print(abs_width, abs_height, bits_per_pixel, compression_method, pad
>ding_size)>ding_size)
87bmp_file = sys.stdin.buffer.read()87bmp_file = sys.stdin.buffer.read()
88read_bmp(bmp_file)88read_bmp(bmp_file)
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