def dqt(flag, name, popper, print_details=False):
"""
DQT
:return:
"""
DQT = {}
length = read_bytes(popper, 2)
content = read_bytes(popper, length - 2, False)
Pq = (content[0] & 0xf0) >> 4
Tq = content[0] & 0x0f
table = content[1:]
if print_details:
idx_seg = 1
idx_seg = print_bytes(length, idx_seg, 2)
print('\t\t\t\t\t\t\t\t', 'Length = {length}'.format(length=length))
idx_seg = print_bytes(content[:1], idx_seg)
print(
'\t\t\t\t\t\t\t\t', '(Pq,Tq)',
'高四位Pq为量化表的数据精确度，Pq=0时，Q0~Qn的值为8位，Pq=1时，Qt的值为16位，Tq表示量化表的编号，为0~3。在基本系统中，Pq=0，Tq=0~1，也就是说最多有两个量化表。'
)
print('\t\t\t\t\t\t\t\t', '(Pq,Tq)=(%d,%d)' % (Pq, Tq))
print_bytes(table, idx_seg)
table = decode_dqt(table, Pq, print_details)
DQT['flag'] = flag
DQT['name'] = name
DQT['length'] = length
DQT['content'] = content
DQT['Pq'] = Pq
DQT['Tq'] = Tq
DQT['table'] = table
return DQT
def sos(flag, name):
SOS = {}
length = read_bytes(2)
content = read_bytes(length - 2, False)
idx_seg = 1
idx_seg = print_bytes(length, idx_seg, 2)
print('\t\t\t\t\t\t\t\t', 'Length = {length}'.format(length=length))
print_bytes(content, idx_seg)
Ns = content[0]
CsTdas = []
for c in range(Ns):
Csn = content[1 + c * 2]
TdnTan = content[2 + c * 2]
CsTdas.append([Csn, TdnTan])
Ss = content[7]
Se = content[8]
AhAl = content[9]
Ah = (AhAl & 0xf0) >> 4
Al = AhAl & 0x0f
SOS['flag'] = flag
SOS['name'] = name
SOS['length'] = length
SOS['Ns'] = Ns
SOS['CsTdas'] = CsTdas
SOS['Ss'] = Ss
SOS['Se'] = Se
SOS['Ah'] = Ah
SOS['Al'] = Al
for k in SOS:
print('\t\t', '%8s' % k, '\t', SOS[k])
SOS['content'] = content
return SOS
def app_0(flag, name):
"""
APP 0
:return:
"""
length = read_bytes(2)
content = read_bytes(length - 2, False)
idx_seg = 1
idx_seg = print_bytes(length, idx_seg, 2)
print('\t\t\t\t\t\t\t\t', 'Length = {length}'.format(length=length))
idx_seg = print_bytes(content, idx_seg)
identifier = bytes_2_int(content[:5])
version = bytes_2_int(content[5:7])
units = content[7]
x_density = bytes_2_int(content[8:10])
y_density = bytes_2_int(content[10:12])
x_thumbnail = content[12]
y_thumbnail = content[13]
print(''' {length:#06X}\tLength\t{length}
{identifier:#012X}\tIdentifier\t{identifier_b}
{version:#06X}\tVersion
{units:#04X}\tUnits\t零时表示未指定，为1表示英寸，为2表示厘米
{x_density:#06X}\tx_density\t{x_density}
{y_density:#06X}\ty_density\t{y_density}
{x_thumbnail:#04X}\tx_thumbnail\t{x_thumbnail}
{y_thumbnail:#04X}\ty_thumbnail\t{y_thumbnail}'''.format(
length=length,
identifier=identifier,
identifier_b=identifier.to_bytes(5, 'big'),
version=version,
units=units,
x_density=x_density,
y_density=y_density,
x_thumbnail=x_thumbnail,
y_thumbnail=y_thumbnail,
))
# remain = length - 16
# if remain > 0:
# remain = read_bytes(remain, False)
# print(remain)
# else:
# remain = b''
remain = content[12:]
return {
'flag': flag,
'name': name,
'length': length,
'identifier': identifier,
'version': version,
'units': units,
'x_density': x_density,
'y_density': y_density,
'x_thumbnail': x_thumbnail,
'y_thumbnail': y_thumbnail,
'data': remain,
'content': content
}
def dht(flag, name, popper, print_details=False):
DHT = {}
length = read_bytes(popper, 2)
content = read_bytes(popper, length - 2, False)
if print_details:
idx_seg = 1
idx_seg = print_bytes(length, idx_seg, 2)
print('\t\t\t\t\t\t\t\t', 'Length = {length}'.format(length=length))
print_bytes(content, idx_seg)
TcTh = content[0]
Tc = (TcTh & 0xf0) >> 4
Th = TcTh & 0x0f
cnts = dict(zip(range(1, 17), content[1:17]))
vals = content[17:]
vals_cur = 0
codes = {}
code_val = 0
for k in cnts:
# print(k, cnts[k])
for cnt in range(cnts[k]):
# print('\t', (bin(val), k))
# # codes[code]={len,value}
# codes[val] = {'len':k,'val':vals[vals_cur]}
# # codes[(code,len)]=value
codes[(code_val, k)] = vals[vals_cur]
vals_cur += 1
code_val += 1
code_val <<= 1
# print()
DHT['flag'] = flag
DHT['name'] = name
DHT['length'] = length
DHT['Tc'] = Tc
DHT['Th'] = Th
DHT['table'] = codes
if print_details:
for k in DHT:
if k == 'table':
print_huf_codes(DHT['table'], print_details)
else:
print('\t\t', '%8s' % k, '\t', DHT[k])
DHT['content'] = content
return DHT
def app_n(flag, name):
"""
APP N
:return:
"""
APP_N = {}
length = read_bytes(2)
content = read_bytes(length - 2, False)
idx_seg = 1
idx_seg = print_bytes(length, idx_seg, 2)
print('\t\t\t\t\t\t\t\t', 'Length = {length}'.format(length=length))
print_bytes(content, idx_seg)
APP_N['flag'] = flag
APP_N['name'] = name
APP_N['length'] = length
APP_N['content'] = content
return APP_N
def sof_0(flag, name, popper, print_details=False):
"""
SOF0
:return:
"""
SOF0 = {}
length = read_bytes(popper, 2)
content = read_bytes(popper, length - 2, False)
if print_details:
idx_seg = 1
idx_seg = print_bytes(length, idx_seg, 2)
print('\t\t\t\t\t\t\t\t', 'Length = {length}'.format(length=length))
print_bytes(content, idx_seg)
P = content[0]
Y = bytes_2_int(content[1:3])
X = bytes_2_int(content[3:5])
Nf = content[5]
Tqs = []
for c in range(Nf):
# 成分编号
Cn = content[6 + c * 3]
# 水平垂直采样因子
HnVn = content[7 + c * 3]
# 量化表编号
Tqn = content[8 + c * 3]
Tqs.append([Cn, HnVn, Tqn])
SOF0['flag'] = flag
SOF0['name'] = name
SOF0['length'] = length
SOF0['P'] = P
SOF0['Y'] = Y
SOF0['X'] = X
SOF0['Nf'] = Nf
SOF0['Tqs'] = Tqs
if print_details:
print('\tSOF0')
for k in SOF0:
print('\t\t', '%8s' % k, '\t', SOF0[k])
SOF0['content'] = content
return SOF0
def read_scan(SCAN=True, show_img=True, print_data=False, print_decode=False):
global cur
_img = img[cur:]
cur = len(img)
# print('data old:')
# print_bytes(_img, 1)
# save_bytes(_img, 1)
# replace 0xff00 and 0xffd9
_cur = 0
scan = b''
while _cur < len(_img):
i = _img[_cur]
if i == 0xff:
i_next = _img[_cur + 1]
if i_next == 0xd9:
print(hex((i << 8) | i_next))
break
elif i_next == 0x00:
# print('Warn! 0xFF00 @cur', _cur + 1)
scan += i.to_bytes(1, 'big')
_cur += 2
continue
elif i_next == 0xff:
print('Warn! 0xFFFF @cur', _cur + 1)
_cur += 1
continue
elif i_next in range(0xd0, 0xd8):
# TODO 0XD0--0XD7，组成RSTn标记，需要忽视整个RSTn标记，即不对当前0XFF和紧接着的0XDn两个字节进行译码，并按RST标记的规则调整译码变量；???
scan += i.to_bytes(1, 'big')
raise Exception('Unimpled')
else:
scan += i.to_bytes(1, 'big')
_cur += 1
# save_bytes(scan, 1)
Y_DC_Huffman_table_id = (headers[0xda][0]['CsTdas'][0][1] >> 4) | 0x00
Y_AC_Huffman_table_id = (headers[0xda][0]['CsTdas'][0][1] & 0x0f) | 0x10
U_DC_Huffman_table_id = (headers[0xda][0]['CsTdas'][1][1] >> 4) | 0x00
U_AC_Huffman_table_id = (headers[0xda][0]['CsTdas'][1][1] & 0x0f) | 0x10
V_DC_Huffman_table_id = (headers[0xda][0]['CsTdas'][2][1] >> 4) | 0x00
V_AC_Huffman_table_id = (headers[0xda][0]['CsTdas'][2][1] & 0x0f) | 0x10
table_ids = [(Y_DC_Huffman_table_id, Y_AC_Huffman_table_id),
(U_DC_Huffman_table_id, U_AC_Huffman_table_id),
(V_DC_Huffman_table_id, V_AC_Huffman_table_id)]
DHTs = {}
for _dht in headers[0xc4]:
DHTs[(_dht['Tc'] << 4) | _dht['Th']] = _dht # ['table']
if print_decode:
print_dht(_dht)
if print_data:
print('data:')
print_bytes(scan, 1)
if not SCAN:
return
if print_data:
print_stream(scan)
# get H123,V123
sof0_Tqs = headers[0xc0][0]['Tqs']
colors_tqs = {}
for tq in sof0_Tqs:
# tq[0]-颜色分量号，-1映射到012
colors_tqs[tq[0] - 1] = {}
# 水平和垂直采样因子
colors_tqs[tq[0] - 1]['H'] = tq[1] >> 4
colors_tqs[tq[0] - 1]['V'] = tq[1] & 0x0f
# MCU 中 data unit(s) 的数量
colors_tqs[tq[0] -
1]['DUC'] = colors_tqs[tq[0] - 1]['H'] * colors_tqs[tq[0] -
1]['V']
# 量化表编号
colors_tqs[tq[0] - 1]['QTable'] = tq[2]
prev = 0
DC = True
got = True
RLE_val = False
code_len = 0
# todo convert to numpy
MCUs = []
mcu = {0: [], 1: [], 2: []}
data_unit = []
in_mcu = True
mcu_idx = 0
current_color = 0
data_unit_idx = 0
# 差分编码
diff = [0, 0, 0]
for i in scan:
ii = i | (prev << 8)
for a in reversed(range(8)):
code_len += 1
t = (ii >> a)
# print(t, bin(t))
if RLE_val:
if code_len >= val_len:
ii &= (0xff >> (8 - a))
# hit the val
RLE_val = decode_b(code_len, t)
if print_decode:
print('RLE', bin(t)[2:].zfill(code_len), RLE_val)
data_unit.append(RLE_val)
code_len = 0
RLE_val = False
if len(data_unit) >= 64:
DC = True
data_unit_idx += 1
# # # todo 差分编码矫正
# # Dc_n = Diff_n-1 + Diff_n
# tmp = data_unit[0]
# data_unit[0] += diff[current_color]
# diff[current_color] = tmp
# Dc_n = Dc_n-1 + Diff_n
data_unit[0] += diff[current_color]
diff[current_color] = data_unit[0]
mcu[current_color].append(data_unit)
data_unit = []
if data_unit_idx >= colors_tqs[current_color]['DUC']:
if print_decode:
print('---Color', colors_YCrCb[current_color],
'end')
current_color += 1
current_color %= 3
data_unit_idx = 0
if current_color == 0:
# todo big image - do add to img sync
mcu = convert_mcu(mcu, colors_tqs)
MCUs.append(mcu)
if print_decode:
print('===MCU', mcu_idx, ' end')
mcu = {0: [], 1: [], 2: []}
mcu_idx += 1
in_mcu = True
continue
if got:
got = False
if DC:
table = DHTs[table_ids[current_color][0]]
else:
table = DHTs[table_ids[current_color][1] | 0x10]
# if t in table['table'] and code_len == table['table'][t]['len']:
if (t, code_len) in table['table']:
# hit the huffman code
got = True
# val = table['table'][(t, code_len)]['val']
val = table['table'][(t, code_len)]
if DC:
if in_mcu and current_color == 0:
if print_decode:
print('===MCU', mcu_idx, '===')
in_mcu = False
if print_decode:
print('---Col', colors_YCrCb[current_color],
'---data unit', data_unit_idx, '---')
print('DC:', end=' ')
print('hcode',
bin(t)[2:].zfill(code_len), 'val',
'{v:#04X}, {v}'.format(v=val))
if val == 0:
# DC = True
# print('Color', colors[current_color], 'end')
# current_color += 1
# current_color %= 3
DC = False
val_len = val
RLE_val = False
# todo dc=0 : append 0
data_unit.append(RLE_val)
else:
DC = False
val_len = val
RLE_val = True
else:
# AC
if print_decode:
print('AC:', end=' ')
print('hcode',
bin(t)[2:].zfill(code_len), 'val',
'{v:#04X}, {v}'.format(v=val))
if val == 0:
DC = True
data_unit_idx += 1
rest_z = 64 - len(data_unit)
if rest_z > 0:
data_unit += [0] * rest_z
# # todo 差分编码矫正
# tmp = data_unit[0]
# data_unit[0] += diff[current_color]
# diff[current_color] = tmp
data_unit[0] += diff[current_color]
diff[current_color] = data_unit[0]
mcu[current_color].append(data_unit)
data_unit = []
if data_unit_idx >= colors_tqs[current_color]['DUC']:
if print_decode:
print('---Color', colors_YCrCb[current_color],
'end')
current_color += 1
current_color %= 3
data_unit_idx = 0
if current_color == 0:
# todo big image - do add to img sync
mcu = convert_mcu(mcu, colors_tqs)
MCUs.append(mcu)
if print_decode:
print('===MCU', mcu_idx, ' end')
mcu = {0: [], 1: [], 2: []}
mcu_idx += 1
in_mcu = True
else:
zero_cnt = val >> 4
if print_decode:
print('\tzero cnt:', zero_cnt)
data_unit += ([0] * zero_cnt)
val_len = val & 0x0f
# todo 应该是0xF0才会到这里，假设16个0后面一定会有AC编码
if val_len == 0:
RLE_val = False
# todo debug AC code == 0xF0 ? zero_cnt=15,+0?
data_unit.append(0)
else:
RLE_val = True
# print('hcode',bin(t)[2:].zfill(table['table'][t]['len']))
# print('hcode', bin(t)[2:].zfill(table['table'][(t, code_len)]),'val','{v:#04X}, {v}'.format(v=val))
ii &= (0xff >> (8 - a))
code_len = 0
prev = ii
# print('===================\nMCUs')
# print(MCUs)
img_show = merge_mcus(MCUs, colors_tqs, headers[0xc0][0])
img_show = crop_image(img_show, headers[0xc0][0])
if show_img:
plt_mcu(img_show)
return img_show