python-pillow/Pillow
1
1
Fork 0
mirror of https://github.com/python-pillow/Pillow.git synced 2024-12-25 09:26:16 +03:00
Code Issues Packages Projects Releases Wiki Activity

Merge pull request #2103 from radarhere/append_images

Browse Source 
Added append_images parameter to GIF saving
This commit is contained in:
wiredfool 2016-09-22 10:21:31 +01:00 committed by GitHub
commit 25797b2baa
3 changed files with 114 additions and 65 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

157
PIL/GifImagePlugin.py
View File

@ -351,34 +351,38 @@ def _save(im, fp, filename, save_all=False):
previous = None
first_frame = None
for im_frame in ImageSequence.Iterator(im):
im_frame = _convert_mode(im_frame)
append_images = im.encoderinfo.get("append_images", [])
for imSequence in [im]+append_images:
for im_frame in ImageSequence.Iterator(imSequence):
encoderinfo = im.encoderinfo.copy()
im_frame = _convert_mode(im_frame)
# To specify duration, add the time in milliseconds to getdata(),
# e.g. getdata(im_frame, duration=1000)
if not previous:
# global header
first_frame = getheader(im_frame, palette, im.encoderinfo)[0]
first_frame += getdata(im_frame, (0, 0), **im.encoderinfo)
else:
if first_frame:
for s in first_frame:
fp.write(s)
first_frame = None
# delta frame
delta = ImageChops.subtract_modulo(im_frame, previous.copy())
bbox = delta.getbbox()
if bbox:
# compress difference
for s in getdata(im_frame.crop(bbox),
bbox[:2], **im.encoderinfo):
fp.write(s)
# To specify duration, add the time in milliseconds to getdata(),
# e.g. getdata(im_frame, duration=1000)
if not previous:
# global header
first_frame = getheader(im_frame, palette, encoderinfo)[0]
first_frame += getdata(im_frame, (0, 0), **encoderinfo)
else:
# FIXME: what should we do in this case?
pass
previous = im_frame
if first_frame:
for s in first_frame:
fp.write(s)
first_frame = None
# delta frame
delta = ImageChops.subtract_modulo(im_frame, previous.copy())
bbox = delta.getbbox()
if bbox:
# compress difference
encoderinfo['include_color_table'] = True
for s in getdata(im_frame.crop(bbox),
bbox[:2], **encoderinfo):
fp.write(s)
else:
# FIXME: what should we do in this case?
pass
previous = im_frame
if first_frame:
save_all = False
if not save_all:
@ -455,7 +459,7 @@ def _get_local_header(fp, im, offset, flags):
fp.write(b"!" +
o8(249) + # extension intro
o8(4) + # length
o8(transparency_flag) + # transparency info present
o8(transparency_flag) + # packed fields
o16(duration) + # duration
o8(transparency) + # transparency index
o8(0))
@ -476,13 +480,27 @@ def _get_local_header(fp, im, offset, flags):
o8(1) +
o16(number_of_loops) + # number of loops
o8(0))
include_color_table = im.encoderinfo.get('include_color_table')
if include_color_table:
try:
palette = im.encoderinfo["palette"]
except KeyError:
palette = None
palette_bytes = _get_palette_bytes(im, palette, im.encoderinfo)[0]
color_table_size = _get_color_table_size(palette_bytes)
if color_table_size:
flags = flags | 128 # local color table flag
flags = flags | color_table_size
fp.write(b"," +
o16(offset[0]) + # offset
o16(offset[1]) +
o16(im.size[0]) + # size
o16(im.size[1]) +
o8(flags) + # flags
o8(8)) # bits
o8(flags)) # flags
if include_color_table and color_table_size:
fp.write(_get_header_palette(palette_bytes))
fp.write(o8(8)) # bits
def _save_netpbm(im, fp, filename):
@ -550,31 +568,25 @@ def _get_used_palette_colors(im):
return used_palette_colors
def _get_color_table_size(palette_bytes):
# calculate the palette size for the header
import math
color_table_size = int(math.ceil(math.log(len(palette_bytes)//3, 2)))-1
if color_table_size < 0:
color_table_size = 0
return color_table_size
def getheader(im, palette=None, info=None):
"""Return a list of strings representing a GIF header"""
def _get_header_palette(palette_bytes):
color_table_size = _get_color_table_size(palette_bytes)
# Header Block
# http://www.matthewflickinger.com/lab/whatsinagif/bits_and_bytes.asp
version = b"87a"
for extensionKey in ["transparency", "duration", "loop", "comment"]:
if info and extensionKey in info:
if ((extensionKey == "duration" and info[extensionKey] == 0) or
(extensionKey == "comment" and not (1 <= len(info[extensionKey]) <= 255))):
continue
version = b"89a"
break
else:
if im.info.get("version") == "89a":
version = b"89a"
header = [
b"GIF"+version + # signature + version
o16(im.size[0]) + # canvas width
o16(im.size[1]) # canvas height
]
# add the missing amount of bytes
# the palette has to be 2<<n in size
actual_target_size_diff = (2 << color_table_size) - len(palette_bytes)//3
if actual_target_size_diff > 0:
palette_bytes += o8(0) * 3 * actual_target_size_diff
return palette_bytes
def _get_palette_bytes(im, palette, info):
if im.mode == "P":
if palette and isinstance(palette, bytes):
source_palette = palette[:768]
@ -617,15 +629,38 @@ def getheader(im, palette=None, info=None):
if not palette_bytes:
palette_bytes = source_palette
return palette_bytes, used_palette_colors
def getheader(im, palette=None, info=None):
"""Return a list of strings representing a GIF header"""
# Header Block
# http://www.matthewflickinger.com/lab/whatsinagif/bits_and_bytes.asp
version = b"87a"
for extensionKey in ["transparency", "duration", "loop", "comment"]:
if info and extensionKey in info:
if ((extensionKey == "duration" and info[extensionKey] == 0) or
(extensionKey == "comment" and not (1 <= len(info[extensionKey]) <= 255))):
continue
version = b"89a"
break
else:
if im.info.get("version") == "89a":
version = b"89a"
header = [
b"GIF"+version + # signature + version
o16(im.size[0]) + # canvas width
o16(im.size[1]) # canvas height
]
palette_bytes, used_palette_colors = _get_palette_bytes(im, palette, info)
# Logical Screen Descriptor
# calculate the palette size for the header
import math
color_table_size = int(math.ceil(math.log(len(palette_bytes)//3, 2)))-1
if color_table_size < 0:
color_table_size = 0
color_table_size = _get_color_table_size(palette_bytes)
# size of global color table + global color table flag
header.append(o8(color_table_size + 128))
header.append(o8(color_table_size + 128)) # packed fields
# background + reserved/aspect
if info and "background" in info:
background = info["background"]
@ -640,14 +675,8 @@ def getheader(im, palette=None, info=None):
header.append(o8(background) + o8(0))
# end of Logical Screen Descriptor
# add the missing amount of bytes
# the palette has to be 2<<n in size
actual_target_size_diff = (2 << color_table_size) - len(palette_bytes)//3
if actual_target_size_diff > 0:
palette_bytes += o8(0) * 3 * actual_target_size_diff
# Header + Logical Screen Descriptor + Global Color Table
header.append(palette_bytes)
header.append(_get_header_palette(palette_bytes))
return header, used_palette_colors

18
Tests/test_file_gif.py
View File

@ -306,6 +306,24 @@ class TestFileGif(PillowTestCase):
reread = Image.open(out)
self.assertEqual(reread.info["version"], b"GIF87a")
def test_append_images(self):
out = self.tempfile('temp.gif')
# Test appending single frame images
im = Image.new('RGB', (100, 100), '#f00')
ims = [Image.new('RGB', (100, 100), color) for color in ['#0f0', '#00f']]
im.save(out, save_all=True, append_images=ims)
reread = Image.open(out)
self.assertEqual(reread.n_frames, 3)
# Tests appending single and multiple frame images
im = Image.open("Tests/images/dispose_none.gif")
ims = [Image.open("Tests/images/dispose_prev.gif")]
im.save(out, save_all=True, append_images=ims)
reread = Image.open(out)
self.assertEqual(reread.n_frames, 10)
if __name__ == '__main__':
unittest.main()

4
docs/handbook/image-file-formats.rst
View File

@ -103,7 +103,9 @@ Saving sequences
When calling :py:meth:`~PIL.Image.Image.save`, if a multiframe image is used,
by default only the first frame will be saved. To save all frames, the
``save_all`` parameter must be present and set to ``True``.
``save_all`` parameter must be present and set to ``True``. To append
additional frames when saving, the ``append_images`` parameter can be set to a
list of images containing the extra frames.
If present, the ``loop`` parameter can be used to set the number of times
the GIF should loop, and the ``duration`` parameter can set the number of