如何在python中将.webp转换为.apng？

Question

我正在尝试将.webp中的动画图像转换为.apng；我尝试了以下方法：

from PIL import Image, ImageSequence
from apng import APNG
im = Image.open('/content/animate_w.webp')
#im.save('/content/animate_w.apng', 'apng', save_all = True, optimize = True, background=0) # not work
im.save('/content/animate_w.png', 'png', save_all = True, optimize = True, background=0)
im = Image.open('/content/animate_w.png')

i = 0
for frame in ImageSequence.Iterator(im):
  ex_command = f'frame_{i} = frame'
  exec(ex_command)
  i += 1


# not really sure what's next
files = [
  ("frame_1.png", 100),
  ("frame_2.png", 200),
  ("frame_3.png", 300)
]

im = APNG()
for file, delay in files:
  im.append_file(file, delay=delay)
im.save("result.apng")

单独保存的框架部分不工作，我不知道下一步如何进行。有什么想法吗？

Answer 1

您有正确的方向，只需添加步骤从webp文件中提取框架。

我希望下面的代码可以添加更多关于如何实现它的想法。

我使用网络工具提取帧

from webptools import webpmux_getframe
from PIL import Image, ImageSequence
from apng import APNG

# Load the webp file
# Downloaded from https://pullzone1-corydowdywebdesi.netdna-ssl.com/assets/blog/apngwebp/squirrel.q70.m6.mixed.webp
im = Image.open('squirrel.q70.m6.mixed.webp')

# Get the number of frames
num_of_frame = 0
for frame in ImageSequence.Iterator(im):
    ex_command = f'frame_{num_of_frame} = frame'
    exec(ex_command)
    num_of_frame += 1

# Extract the frames
list_of_files = []
for i in range(num_of_frame):
    webpmux_getframe(input_image='squirrel.q70.m6.mixed.webp', output_image=f'output_frame{i}.png', frame_number=i)
    list_of_files.append(f'output_frame{i}.png')

# Save to APNG
im = APNG()
for filename in list_of_files:
    im.append_file(filename)
im.save('result.apng')

# Load frame from APNG file
im = APNG.open('result.apng')
for i, (png, control) in enumerate(im.frames):
    png.save(f'apng_frame_{i}.png')

另一个不使用webptools的解决方案是使用PIL中的WebPimageFile。

from PIL import WebPImagePlugin
from apng import APNG

# Load webp and extract the frames
imwebp = WebPImagePlugin.WebPImageFile('squirrel.q70.m6.mixed.webp')
nframes = 0
list_of_files = []
while imwebp:
    imwebp.seek(nframes)
    imwebp.save(f'output_frame{nframes}.png', 'PNG')
    list_of_files.append(f'output_frame{nframes}.png')
    nframes += 1
    try:
        imwebp.seek(nframes)
    except EOFError:
        break

# Save to APNG
im = APNG()
for filename in list_of_files:
    im.append_file(filename)
im.save('result.apng')

# Load frame from APNG file
im = APNG.open('result.apng')
for i, (png, control) in enumerate(im.frames):
    png.save(f'apng_frame_{i}.png')

Answer 2

from PIL import WebPImagePlugin
from PIL.PngImagePlugin import Disposal

webp_file = WebPImagePlugin.WebPImageFile("file.webp")
frame_idx = 0
frames = []
while True:
    try:
        webp_file.seek(frame_idx)
        frames.append(webp_file.copy())
        frame_idx += 1
    except EOFError:
        break
frames[0].save("file.apng", save_all=True, append_images=frames[1:], duration=webp_file.info["duration"], disposal=Disposal.OP_BACKGROUND)

不需要pyAPNG。