# Copyright (C) 2012, Almar Klein
#
# This code is subject to the (new) BSD license:
#
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# modification, are permitted provided that the following conditions are met:
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
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# * Neither the name of the <organization> nor the
# names of its contributors may be used to endorse or promote products
# derived from this software without specific prior written permission.
#
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# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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""" Module images2swf
Provides a function (writeSwf) to store a series of PIL images or numpy
arrays in an SWF movie, that can be played on a wide range of OS's.
This module came into being because I wanted to store a series of images
in a movie that can be viewed by other people, and which I can embed in
flash presentations. For writing AVI or MPEG you really need a c/c++
library, and although the filesize is then very small, the quality is
sometimes not adequate. Besides I'd like to be independent of yet another
package. I tried writing animated gif using PIL (which is widely available),
but the quality is so poor because it only allows for 256 different colors.
[EDIT: thanks to Ant1, now the quality of animated gif isn't so bad!]
I also looked into MNG and APNG, two standards similar to the PNG stanard.
Both standards promise exactly what I need. However, hardly any application
can read those formats, and I cannot import them in flash.
Therefore I decided to check out the swf file format, which is very well
documented. This is the result: a pure python module to create an SWF file
that shows a series of images. The images are stored using the DEFLATE
algorithm (same as PNG and ZIP and which is included in the standard Python
distribution). As this compression algorithm is much more effective than
that used in GIF images, we obtain better quality (24 bit colors + alpha
channel) while still producesing smaller files (a test showed ~75%).
Although SWF also allows for JPEG compression, doing so would probably
require a third party library (because encoding JPEG is much harder).
This module requires Python 2.x and numpy.
sources and tools:
- SWF on wikipedia
- Adobes "SWF File Format Specification" version 10
(http://www.adobe.com/devnet/swf/pdf/swf_file_format_spec_v10.pdf)
- swftools (swfdump in specific) for debugging
- iwisoft swf2avi can be used to convert swf to avi/mpg/flv with really
good quality, while file size is reduced with factors 20-100.
A good program in my opinion. The free version has the limitation
of a watermark in the upper left corner.
"""
from __future__ import annotations
import os
import zlib
try:
import numpy as np
except ImportError:
np = None
try:
import PIL.Image
except ImportError:
PIL = None
string_types = (str,)
integer_types = (int,)
class_types = (type,)
text_type = str
binary_type = bytes
# todo: use imageio/FreeImage to support reading JPEG images from SWF?
[docs]def checkImages(images):
"""checkImages(images)
Check numpy images and correct intensity range etc.
The same for all movie formats.
"""
# Init results
images2 = []
for im in images:
if PIL and isinstance(im, PIL.Image.Image):
# We assume PIL images are alright
images2.append(im)
elif np and isinstance(im, np.ndarray):
# Check and convert dtype
if im.dtype == np.uint8:
images2.append(im) # Ok
elif im.dtype in [np.float32, np.float64]:
theMax = im.max()
if theMax > 128 and theMax < 300:
pass # assume 0:255
else:
im = im.copy()
im[im < 0] = 0
im[im > 1] = 1
im *= 255
images2.append(im.astype(np.uint8))
else:
im = im.astype(np.uint8)
images2.append(im)
# Check size
if im.ndim == 2:
pass # ok
elif im.ndim == 3:
if im.shape[2] not in [3, 4]:
msg = "This array can not represent an image."
raise ValueError(msg)
else:
msg = "This array can not represent an image."
raise ValueError(msg)
else:
raise ValueError("Invalid image type: " + str(type(im)))
# Done
return images2
# Base functions and classes
[docs]class BitArray:
"""Dynamic array of bits that automatically resizes
with factors of two.
Append bits using .Append() or +=
You can reverse bits using .Reverse()
"""
def __init__(self, initvalue=None):
self.data = np.zeros((16,), dtype=np.uint8)
self._len = 0
if initvalue is not None:
self.Append(initvalue)
def __len__(self):
return self._len # self.data.shape[0]
def __repr__(self):
return self.data[: self._len].tobytes()
def _checkSize(self):
# check length... grow if necessary
arraylen = self.data.shape[0]
if self._len >= arraylen:
tmp = np.zeros((arraylen * 2,), dtype=np.uint8)
tmp[: self._len] = self.data[: self._len]
self.data = tmp
def __add__(self, value):
self.Append(value)
return self
[docs] def Append(self, bits):
# check input
if isinstance(bits, BitArray):
bits = str(bits)
if isinstance(bits, int):
bits = str(bits)
if not isinstance(bits, string_types):
msg = "Append bits as strings or integers!"
raise ValueError(msg)
# add bits
for bit in bits:
self.data[self._len] = ord(bit)
self._len += 1
self._checkSize()
[docs] def Reverse(self):
"""In-place reverse."""
tmp = self.data[: self._len].copy()
self.data[: self._len] = np.flipud(tmp)
[docs] def ToBytes(self):
"""Convert to bytes. If necessary,
zeros are padded to the end (right side).
"""
bits = str(self)
# determine number of bytes
nbytes = 0
while nbytes * 8 < len(bits):
nbytes += 1
# pad
bits = bits.ljust(nbytes * 8, "0")
# go from bits to bytes
bb = binary_type()
for i in range(nbytes):
tmp = int(bits[i * 8 : (i + 1) * 8], 2)
bb += intToUint8(tmp)
# done
return bb
[docs]def intToUint32(i):
return int(i).to_bytes(4, "little")
[docs]def intToUint16(i):
return int(i).to_bytes(2, "little")
[docs]def intToUint8(i):
return int(i).to_bytes(1, "little")
[docs]def intToBits(i: int, n: int | None = None) -> BitArray:
"""convert int to a string of bits (0's and 1's in a string),
pad to n elements. Convert back using int(ss,2)."""
ii = i
# make bits
bb = BitArray()
while ii > 0:
bb += str(ii % 2)
ii >>= 1
bb.Reverse()
# justify
if n is not None:
if len(bb) > n:
msg = f"{intToBits.__name__} fail: len larger than padlength."
raise ValueError(msg)
bb = str(bb).rjust(n, "0")
# done
return BitArray(bb)
[docs]def bitsToInt(bb, n=8):
# Init
value = ""
# Get value in bits
for i in range(len(bb)):
b = bb[i : i + 1]
tmp = f"{ord(b):b}"
# value += tmp.rjust(8,'0')
value = tmp.rjust(8, "0") + value
# Make decimal
return int(value[:n], 2)
[docs]def getTypeAndLen(bb):
"""bb should be 6 bytes at least
Return (type, length, length_of_full_tag)
"""
# Init
value = ""
# Get first 16 bits
for i in range(2):
b = bb[i : i + 1]
tmp = f"{ord(b):b}"
# value += tmp.rjust(8,'0')
value = tmp.rjust(8, "0") + value
# Get type and length
type = int(value[:10], 2)
L = int(value[10:], 2)
L2 = L + 2
# Long tag header?
if L == 63: # '111111'
value = ""
for i in range(2, 6):
b = bb[i : i + 1] # becomes a single-byte bytes() on both PY3 and PY2
tmp = f"{ord(b):b}"
# value += tmp.rjust(8,'0')
value = tmp.rjust(8, "0") + value
L = int(value, 2)
L2 = L + 6
# Done
return type, L, L2
[docs]def signedIntToBits(i: int, n: int | None = None) -> BitArray:
"""convert signed int to a string of bits (0's and 1's in a string),
pad to n elements. Negative numbers are stored in 2's complement bit
patterns, thus positive numbers always start with a 0.
"""
# negative number?
ii = i
if i < 0:
# A negative number, -n, is represented as the bitwise opposite of
ii = abs(ii) - 1 # the positive-zero number n-1.
# make bits
bb = BitArray()
while ii > 0:
bb += str(ii % 2)
ii >>= 1
bb.Reverse()
# justify
bb = "0" + str(bb) # always need the sign bit in front
if n is not None:
if len(bb) > n:
msg = f"{signedIntToBits.__name__} fail: len larger than padlength."
raise ValueError(msg)
bb = bb.rjust(n, "0")
# was it negative? (then opposite bits)
if i < 0:
bb = bb.replace("0", "x").replace("1", "0").replace("x", "1")
# done
return BitArray(bb)
[docs]def twitsToBits(arr):
"""Given a few (signed) numbers, store them
as compactly as possible in the wat specifief by the swf format.
The numbers are multiplied by 20, assuming they
are twits.
Can be used to make the RECT record.
"""
# first determine length using non justified bit strings
maxlen = 1
for i in arr:
tmp = len(signedIntToBits(i * 20))
maxlen = max(tmp, maxlen)
# build array
bits = intToBits(maxlen, 5)
for i in arr:
bits += signedIntToBits(i * 20, maxlen)
return bits
[docs]def floatsToBits(arr):
"""Given a few (signed) numbers, convert them to bits,
stored as FB (float bit values). We always use 16.16.
Negative numbers are not (yet) possible, because I don't
know how the're implemented (ambiguity).
"""
bits = intToBits(31, 5) # 32 does not fit in 5 bits!
for i in arr:
if i < 0:
msg = "Dit not implement negative floats!"
raise ValueError(msg)
i1 = int(i)
i2 = i - i1
bits += intToBits(i1, 15)
bits += intToBits(i2 * 2**16, 16)
return bits
def _readFrom(fp, n):
bb = binary_type()
try:
while len(bb) < n:
tmp = fp.read(n - len(bb))
bb += tmp
if not tmp:
break
except EOFError:
pass
return bb
# Base Tag
[docs]class Tag:
def __init__(self):
self.bytes = binary_type()
self.tagtype = -1
[docs] def ProcessTag(self):
"""Implement this to create the tag."""
raise NotImplementedError
[docs] def GetTag(self):
"""Calls processTag and attaches the header."""
self.ProcessTag()
# tag to binary
bits = intToBits(self.tagtype, 10)
# complete header uint16 thing
bits += "1" * 6 # = 63 = 0x3f
# make uint16
bb = intToUint16(int(str(bits), 2))
# now add 32bit length descriptor
bb += intToUint32(len(self.bytes))
# done, attach and return
bb += self.bytes
return bb
[docs] def MakeRectRecord(self, xmin, xmax, ymin, ymax):
"""Simply uses makeCompactArray to produce
a RECT Record."""
return twitsToBits([xmin, xmax, ymin, ymax])
[docs] def MakeMatrixRecord(self, scale_xy=None, rot_xy=None, trans_xy=None):
# empty matrix?
if scale_xy is None and rot_xy is None and trans_xy is None:
return "0" * 8
# init
bits = BitArray()
# scale
if scale_xy:
bits += "1"
bits += floatsToBits([scale_xy[0], scale_xy[1]])
else:
bits += "0"
# rotation
if rot_xy:
bits += "1"
bits += floatsToBits([rot_xy[0], rot_xy[1]])
else:
bits += "0"
# translation (no flag here)
if trans_xy:
bits += twitsToBits([trans_xy[0], trans_xy[1]])
else:
bits += twitsToBits([0, 0])
# done
return bits
# Control tags
[docs]class ControlTag(Tag):
def __init__(self):
Tag.__init__(self)
[docs]class FileAttributesTag(ControlTag):
def __init__(self):
ControlTag.__init__(self)
self.tagtype = 69
[docs] def ProcessTag(self):
self.bytes = "\x00".encode("ascii") * (1 + 3)
[docs]class SetBackgroundTag(ControlTag):
"""Set the color in 0-255, or 0-1 (if floats given)."""
def __init__(self, *rgb):
self.tagtype = 9
if len(rgb) == 1:
rgb = rgb[0]
self.rgb = rgb
[docs] def ProcessTag(self):
bb = binary_type()
for i in range(3):
clr = self.rgb[i]
if isinstance(clr, float):
clr *= 255
bb += intToUint8(clr)
self.bytes = bb
[docs]class DoActionTag(Tag):
def __init__(self, action="stop"):
Tag.__init__(self)
self.tagtype = 12
self.actions = [action]
[docs] def Append(self, action):
self.actions.append(action)
[docs] def ProcessTag(self):
bb = binary_type()
for action in self.actions:
action = action.lower()
if action == "stop":
bb += "\x07".encode("ascii")
elif action == "play":
bb += "\x06".encode("ascii")
else:
print("warning, unknown action: %s" % action)
bb += intToUint8(0)
self.bytes = bb
# Definition tags
[docs]class DefinitionTag(Tag):
counter = 0 # to give automatically id's
def __init__(self):
Tag.__init__(self)
DefinitionTag.counter += 1
self.id = DefinitionTag.counter # id in dictionary
[docs]class BitmapTag(DefinitionTag):
def __init__(self, im):
DefinitionTag.__init__(self)
self.tagtype = 36 # DefineBitsLossless2
# convert image (note that format is ARGB)
# even a grayscale image is stored in ARGB, nevertheless,
# the fabilous deflate compression will make it that not much
# more data is required for storing (25% or so, and less than 10%
# when storing RGB as ARGB).
if len(im.shape) == 3:
if im.shape[2] in [3, 4]:
tmp = np.ones((im.shape[0], im.shape[1], 4), dtype=np.uint8) * 255
for i in range(3):
tmp[:, :, i + 1] = im[:, :, i]
if im.shape[2] == 4:
tmp[:, :, 0] = im[:, :, 3] # swap channel where alpha is in
else:
msg = "Invalid shape to be an image."
raise ValueError(msg)
elif len(im.shape) == 2:
tmp = np.ones((im.shape[0], im.shape[1], 4), dtype=np.uint8) * 255
for i in range(3):
tmp[:, :, i + 1] = im[:, :]
else:
msg = "Invalid shape to be an image."
raise ValueError(msg)
# we changed the image to uint8 4 channels.
# now compress!
self._data = zlib.compress(tmp.tostring(), zlib.DEFLATED)
self.imshape = im.shape
[docs] def ProcessTag(self):
# build tag
bb = binary_type()
bb += intToUint16(self.id) # CharacterID
bb += intToUint8(5) # BitmapFormat
bb += intToUint16(self.imshape[1]) # BitmapWidth
bb += intToUint16(self.imshape[0]) # BitmapHeight
bb += self._data # ZlibBitmapData
self.bytes = bb
[docs]class PlaceObjectTag(ControlTag):
def __init__(self, depth, idToPlace=None, xy=(0, 0), move=False):
ControlTag.__init__(self)
self.tagtype = 26
self.depth = depth
self.idToPlace = idToPlace
self.xy = xy
self.move = move
[docs] def ProcessTag(self):
# retrieve stuff
depth = self.depth
xy = self.xy
id = self.idToPlace
# build PlaceObject2
bb = binary_type()
if self.move:
bb += "\x07".encode("ascii")
else:
bb += "\x06".encode("ascii") # (8 bit flags): 4:matrix, 2:character, 1:move
bb += intToUint16(depth) # Depth
bb += intToUint16(id) # character id
bb += self.MakeMatrixRecord(trans_xy=xy).ToBytes() # MATRIX record
self.bytes = bb
[docs]class ShapeTag(DefinitionTag):
def __init__(self, bitmapId, xy, wh):
DefinitionTag.__init__(self)
self.tagtype = 2
self.bitmapId = bitmapId
self.xy = xy
self.wh = wh
[docs] def ProcessTag(self):
"""Returns a defineshape tag. with a bitmap fill"""
bb = binary_type()
bb += intToUint16(self.id)
xy, wh = self.xy, self.wh
tmp = self.MakeRectRecord(xy[0], wh[0], xy[1], wh[1]) # ShapeBounds
bb += tmp.ToBytes()
# make SHAPEWITHSTYLE structure
# first entry: FILLSTYLEARRAY with in it a single fill style
bb += intToUint8(1) # FillStyleCount
bb += "\x41".encode(
"ascii"
) # FillStyleType (0x41 or 0x43, latter is non-smoothed)
bb += intToUint16(self.bitmapId) # BitmapId
# bb += '\x00' # BitmapMatrix (empty matrix with leftover bits filled)
bb += self.MakeMatrixRecord(scale_xy=(20, 20)).ToBytes()
# # first entry: FILLSTYLEARRAY with in it a single fill style
# bb += intToUint8(1) # FillStyleCount
# bb += '\x00' # solid fill
# bb += '\x00\x00\xff' # color
# second entry: LINESTYLEARRAY with a single line style
bb += intToUint8(0) # LineStyleCount
# bb += intToUint16(0*20) # Width
# bb += '\x00\xff\x00' # Color
# third and fourth entry: NumFillBits and NumLineBits (4 bits each)
# I each give them four bits, so 16 styles possible.
bb += "\x44".encode("ascii")
self.bytes = bb
# last entries: SHAPERECORDs ... (individual shape records not aligned)
# STYLECHANGERECORD
bits = BitArray()
bits += self.MakeStyleChangeRecord(0, 1, moveTo=(self.wh[0], self.wh[1]))
# STRAIGHTEDGERECORD 4x
bits += self.MakeStraightEdgeRecord(-self.wh[0], 0)
bits += self.MakeStraightEdgeRecord(0, -self.wh[1])
bits += self.MakeStraightEdgeRecord(self.wh[0], 0)
bits += self.MakeStraightEdgeRecord(0, self.wh[1])
# ENDSHAPRECORD
bits += self.MakeEndShapeRecord()
self.bytes += bits.ToBytes()
# done
# self.bytes = bb
[docs] def MakeStyleChangeRecord(self, lineStyle=None, fillStyle=None, moveTo=None):
# first 6 flags
# Note that we use FillStyle1. If we don't flash (at least 8) does not
# recognize the frames properly when importing to library.
bits = BitArray()
bits += "0" # TypeFlag (not an edge record)
bits += "0" # StateNewStyles (only for DefineShape2 and Defineshape3)
if lineStyle:
bits += "1" # StateLineStyle
else:
bits += "0"
if fillStyle:
bits += "1" # StateFillStyle1
else:
bits += "0"
bits += "0" # StateFillStyle0
if moveTo:
bits += "1" # StateMoveTo
else:
bits += "0"
# give information
# todo: nbits for fillStyle and lineStyle is hard coded.
if moveTo:
bits += twitsToBits([moveTo[0], moveTo[1]])
if fillStyle:
bits += intToBits(fillStyle, 4)
if lineStyle:
bits += intToBits(lineStyle, 4)
return bits
# return bitsToBytes(bits)
[docs] def MakeStraightEdgeRecord(self, *dxdy):
if len(dxdy) == 1:
dxdy = dxdy[0]
# determine required number of bits
xbits = signedIntToBits(dxdy[0] * 20)
ybits = signedIntToBits(dxdy[1] * 20)
nbits = max([len(xbits), len(ybits)])
bits = BitArray()
bits += "11" # TypeFlag and StraightFlag
bits += intToBits(nbits - 2, 4)
bits += "1" # GeneralLineFlag
bits += signedIntToBits(dxdy[0] * 20, nbits)
bits += signedIntToBits(dxdy[1] * 20, nbits)
# note: I do not make use of vertical/horizontal only lines...
return bits
# return bitsToBytes(bits)
[docs] def MakeEndShapeRecord(self):
bits = BitArray()
bits += "0" # TypeFlag: no edge
bits += "0" * 5 # EndOfShape
return bits
# return bitsToBytes(bits)
# Last few functions
[docs]def buildFile(fp, taglist, nframes=1, framesize=(500, 500), fps=10, version=8):
"""Give the given file (as bytes) a header."""
# compose header
bb = binary_type()
bb += "F".encode("ascii") # uncompressed
bb += "WS".encode("ascii") # signature bytes
bb += intToUint8(version) # version
bb += "0000".encode("ascii") # FileLength (leave open for now)
bb += Tag().MakeRectRecord(0, framesize[0], 0, framesize[1]).ToBytes()
bb += intToUint8(0) + intToUint8(fps) # FrameRate
bb += intToUint16(nframes)
fp.write(bb)
# produce all tags
for tag in taglist:
fp.write(tag.GetTag())
# finish with end tag
fp.write("\x00\x00".encode("ascii"))
# set size
sze = fp.tell()
fp.seek(4)
fp.write(intToUint32(sze))
[docs]def writeSwf(filename, images, duration=0.1, repeat=True):
"""Write an swf-file from the specified images. If repeat is False,
the movie is finished with a stop action. Duration may also
be a list with durations for each frame (note that the duration
for each frame is always an integer amount of the minimum duration.)
Images should be a list consisting of PIL images or numpy arrays.
The latter should be between 0 and 255 for integer types, and
between 0 and 1 for float types.
"""
# Check NumPy
if np is None:
msg = "Need NumPy to write an SWF file."
raise RuntimeError(msg)
# Check images (make all NumPy)
images2 = []
images = checkImages(images)
if not images:
msg = "Image list is empty!"
raise ValueError(msg)
for im in images:
if PIL and isinstance(im, PIL.Image.Image):
if im.mode == "P":
im = im.convert()
im = np.asarray(im)
if len(im.shape) == 0:
msg = "Too little memory to convert PIL image to array"
raise MemoryError(msg)
images2.append(im)
# Init
taglist = [FileAttributesTag(), SetBackgroundTag(0, 0, 0)]
# Check duration
if hasattr(duration, "__len__"):
if len(duration) == len(images2):
duration = list(duration)
else:
msg = "len(duration) doesn't match amount of images."
raise ValueError(msg)
else:
duration = [duration for im in images2]
# Build delays list
minDuration = float(min(duration))
delays = [round(d / minDuration) for d in duration]
delays = [max(1, int(d)) for d in delays]
# Get FPS
fps = 1.0 / minDuration
# Produce series of tags for each image
nframes = 0
for im in images2:
bm = BitmapTag(im)
wh = (im.shape[1], im.shape[0])
sh = ShapeTag(bm.id, (0, 0), wh)
po = PlaceObjectTag(1, sh.id, move=nframes > 0)
taglist.extend([bm, sh, po])
for i in range(delays[nframes]):
taglist.append(ShowFrameTag())
nframes += 1
if not repeat:
taglist.append(DoActionTag("stop"))
# Build file
fp = open(filename, "wb")
try:
buildFile(fp, taglist, nframes=nframes, framesize=wh, fps=fps)
finally:
fp.close()
def _readPixels(bb, i, tagType, L1):
"""With pf's seed after the recordheader, reads the pixeldata."""
# Check NumPy
if np is None:
msg = "Need NumPy to read an SWF file."
raise RuntimeError(msg)
# Get info
# charId = bb[i : i + 2] # unused
i += 2
format = ord(bb[i : i + 1])
i += 1
width = bitsToInt(bb[i : i + 2], 16)
i += 2
height = bitsToInt(bb[i : i + 2], 16)
i += 2
# If we can, get pixeldata and make numpy array
if format != 5:
print("Can only read 24bit or 32bit RGB(A) lossless images.")
else:
# Read byte data
offset = 2 + 1 + 2 + 2 # all the info bits
bb2 = bb[i : i + (L1 - offset)]
# Decompress and make numpy array
data = zlib.decompress(bb2)
a = np.frombuffer(data, dtype=np.uint8)
# Set shape
if tagType == 20:
# DefineBitsLossless - RGB data
try:
a.shape = height, width, 3
except Exception:
# Byte align stuff might cause troubles
print("Cannot read image due to byte alignment")
if tagType == 36:
# DefineBitsLossless2 - ARGB data
a.shape = height, width, 4
# Swap alpha channel to make RGBA
b = a
a = np.zeros_like(a)
a[:, :, 0] = b[:, :, 1]
a[:, :, 1] = b[:, :, 2]
a[:, :, 2] = b[:, :, 3]
a[:, :, 3] = b[:, :, 0]
return a
[docs]def readSwf(filename, asNumpy=True):
"""Read all images from an SWF (shockwave flash) file. Returns a list
of numpy arrays, or, if asNumpy is false, a list if PIL images.
Limitation: only read the PNG encoded images (not the JPG encoded ones).
"""
# Check whether it exists
if not os.path.isfile(filename):
raise OSError("File not found: " + str(filename))
# Check PIL
if (not asNumpy) and (PIL is None):
msg = "Need PIL to return as PIL images."
raise RuntimeError(msg)
# Check NumPy
if np is None:
msg = "Need NumPy to read SWF files."
raise RuntimeError(msg)
# Init images
images = []
# Open file and read all
fp = open(filename, "rb")
bb = fp.read()
try:
# Check opening tag
tmp = bb[0:3].decode("ascii", "ignore")
if tmp.upper() == "FWS":
pass # ok
elif tmp.upper() == "CWS":
# Decompress movie
bb = bb[:8] + zlib.decompress(bb[8:])
else:
raise OSError("Not a valid SWF file: " + str(filename))
# Set filepointer at first tag (skipping framesize RECT and two uin16's
i = 8
nbits = bitsToInt(bb[i : i + 1], 5) # skip FrameSize
nbits = 5 + nbits * 4
Lrect = nbits / 8.0
if Lrect % 1:
Lrect += 1
Lrect = int(Lrect)
i += Lrect + 4
# Iterate over the tags
counter = 0
while True:
counter += 1
# Get tag header
head = bb[i : i + 6]
if not head:
break # Done (we missed end tag)
# Determine type and length
T, L1, L2 = getTypeAndLen(head)
if not L2:
print("Invalid tag length, could not proceed")
break
# print(T, L2)
# Read image if we can
if T in [20, 36]:
im = _readPixels(bb, i + 6, T, L1)
if im is not None:
images.append(im)
elif T in [6, 21, 35, 90]:
print("Ignoring JPEG image: cannot read JPEG.")
else:
pass # Not an image tag
# Detect end tag
if T == 0:
break
# Next tag!
i += L2
finally:
fp.close()
# Convert to normal PIL images if needed
if not asNumpy:
images2 = images
images = []
for im in images2:
images.append(PIL.Image.fromarray(im))
# Done
return images
