Python Pillow Gif 图像伪影/背景

3
目标:最终每一帧都应该有一个完整的木守宫。gif中非木守宫部分应该是透明的(白色也可以)。我的最终目标是能够重新着色,所以我必须能够区分背景与神奇宝贝。
我使用requests从网站获取gif,然后使用pillow获取帧。当我浏览帧时,伪影(主要是背景)干扰了我的处理方法。我使用https://ezgif.com/split来检查它应该看起来如何。
我在我的拼贴作品中放置了框架、处置方法和处置范围周围的框,以帮助看出它应该如何堆叠(如下图所示)。我放了底部的示例代码,将显示重建的帧。
那么我如何使用pillow正确地获取干净的帧呢?

图片

注意:

  • 对于枕头框架索引4,在身体和框架索引27中会出现白线。多个框架中的珠子/分支缺少绿色。
  • 要在ezgif.com上查看我发布的图片,您必须选择“忽略优化”,但我想要的最终照片是网站选项“从前一帧的详细信息重新绘制每一帧”所显示的。

使用的Gif:https://play.pokemonshowdown.com/sprites/xyani/sudowoodo.gif

Pillow结果:
Pillow提取的帧
Ezgif的结果:
网站提取


代码

Python版本
Python == 3.6.4
Pillow == 7.0.0
requests == 2.23.0

from PIL import Image, ImageDraw, ImageFont
from io import BytesIO
import requests

#Depends on the dispose_method and disposal_extent will process accordingly
def method_dispose(i, frames, previous_frame):
    # 0 PIL = Overlay and pass
    # 1 PIL = Overlay and return previous
    # 2 PIL = Erase Overlay
    new_frame = previous_frame.copy()
    current_frame = frames.convert('RGBA')
    new_frame.alpha_composite(current_frame, dest=frames.dispose_extent[0:2], source=frames.dispose_extent)
    if frames.disposal_method is 0:
        return new_frame, Image.new('RGBA', box=frames.size)
    elif frames.disposal_method is 1:
        return new_frame, new_frame.copy()
    elif frames.disposal_method is 2:
        draw = ImageDraw.Draw(previous_frame)
        draw.rectangle(frames.dispose_extent, fill=(255, 255, 255, 0)) #fill white transparent
        return new_frame, previous_frame.copy()

# Goes through the frames and pastes them next to each other then shows
def simpleCollage(frames, num_images_width : int = 5, num_images_height : int = 10):
    width, height = frames.size
    compilation = Image.new('RGBA', size=(width * num_images_width, height * num_images_height))
    fnt = ImageFont.load_default().font
    for i in range(frames.n_frames):
        frames.seek(i)
        the_frame = frames.convert('RGBA')
        draw = ImageDraw.Draw(the_frame)
        draw.rectangle(frames.dispose_extent, outline=(255,173,0,255))
        draw.text((0,0), f"F{i}-M{frames.disposal_method}", font=fnt, fill=(255, 0, 0))
        compilation.paste(the_frame, box=(width * int(i % num_images_width), height * int(i / num_images_width)))
        if i == (num_images_width * num_images_height):
            break;
    compilation.show()

response = requests.get("https://play.pokemonshowdown.com/sprites/xyani/sudowoodo.gif")
frames = Image.open(BytesIO(response.content))
simpleCollage(frames)

width, height = frames.size
all_frames = []
pass_frame = Image.new('RGBA', size=frames.size)
for i in range(frames.n_frames):
    frames.seek(i)
    disp_frame, pass_frame = method_dispose(i, frames, pass_frame)
    all_frames.append(disp_frame)

all_frames[0].save(fp="test.gif", format='GIF', save_all=True, append_images=all_frames[1:], optimize=False, duration=frames.info['duration'], loop=0)
simpleCollage(Image.open("test.gif"))

我用于处理方法的一些来源:

2个回答

1
由于重复使用 .convert() 导致产生了不良的图像结果。为解决这个问题,在 .convert() 后需要加上 .seek(0)。因此,最终代码应该如下所示:
for i in range(frames.n_frames):
    frames.seek(i)
    disp_frame, pass_frame = method_dispose(i, frames, pass_frame)
    all_frames.append(disp_frame)
    frames.seek(0) # <-- Added

0

这不是一个完全经过测试、完全解决的答案,而是我想保存和分享的一个正在进行中的工作,因为我现在必须离开,对于其他人查看此内容可能会有用。

使用ImageMagick可以检查GIF中帧的范围、处理、延迟等信息,方法如下:

identify -format "%f[%s] canvas=%Wx%H size=%wx%h offset=%X%Y %D %Tcentisecs\n" treething.gif 

样例输出

treething.gif[0] canvas=58x66 size=58x66 offset=+0+0 Background 3centisecs
treething.gif[1] canvas=58x66 size=58x66 offset=+0+0 None 3centisecs
treething.gif[2] canvas=58x66 size=49x63 offset=+7+1 None 3centisecs
treething.gif[3] canvas=58x66 size=55x47 offset=+2+1 Background 3centisecs
treething.gif[4] canvas=58x66 size=56x64 offset=+2+1 Background 3centisecs
treething.gif[5] canvas=58x66 size=56x64 offset=+2+1 Background 3centisecs
treething.gif[6] canvas=58x66 size=56x64 offset=+2+1 Background 3centisecs
treething.gif[7] canvas=58x66 size=56x64 offset=+2+1 Background 3centisecs
treething.gif[8] canvas=58x66 size=56x64 offset=+2+1 None 3centisecs
treething.gif[9] canvas=58x66 size=54x65 offset=+3+1 Background 3centisecs
treething.gif[10] canvas=58x66 size=54x65 offset=+3+1 Background 3centisecs
treething.gif[11] canvas=58x66 size=54x65 offset=+3+1 None 3centisecs
treething.gif[12] canvas=58x66 size=45x58 offset=+7+6 Background 3centisecs
treething.gif[13] canvas=58x66 size=51x58 offset=+7+6 Background 3centisecs
treething.gif[14] canvas=58x66 size=55x64 offset=+2+0 Background 3centisecs
treething.gif[15] canvas=58x66 size=55x64 offset=+2+0 Background 3centisecs
treething.gif[16] canvas=58x66 size=55x64 offset=+2+0 Background 3centisecs
treething.gif[17] canvas=58x66 size=55x64 offset=+2+0 None 3centisecs
treething.gif[18] canvas=58x66 size=41x53 offset=+16+4 Background 3centisecs
treething.gif[19] canvas=58x66 size=56x60 offset=+1+4 None 3centisecs
treething.gif[20] canvas=58x66 size=19x61 offset=+9+3 None 3centisecs
treething.gif[21] canvas=58x66 size=43x54 offset=+8+10 None 3centisecs
treething.gif[22] canvas=58x66 size=43x47 offset=+8+10 None 3centisecs
treething.gif[23] canvas=58x66 size=50x61 offset=+1+3 Background 3centisecs
treething.gif[24] canvas=58x66 size=51x61 offset=+1+3 None 3centisecs
treething.gif[25] canvas=58x66 size=43x50 offset=+7+4 None 3centisecs
treething.gif[26] canvas=58x66 size=47x65 offset=+10+1 Background 3centisecs
treething.gif[27] canvas=58x66 size=50x65 offset=+7+1 None 3centisecs
treething.gif[28] canvas=58x66 size=47x64 offset=+3+0 Background 3centisecs
treething.gif[29] canvas=58x66 size=56x64 offset=+2+0 Background 3centisecs
treething.gif[30] canvas=58x66 size=58x64 offset=+0+0 Background 3centisecs
treething.gif[31] canvas=58x66 size=58x64 offset=+0+0 Background 3centisecs
treething.gif[32] canvas=58x66 size=58x64 offset=+0+0 None 3centisecs
treething.gif[33] canvas=58x66 size=37x59 offset=+15+2 Background 3centisecs
treething.gif[34] canvas=58x66 size=48x63 offset=+7+1 Background 3centisecs
treething.gif[35] canvas=58x66 size=48x63 offset=+7+1 Background 3centisecs
treething.gif[36] canvas=58x66 size=50x63 offset=+7+1 Background 3centisecs
treething.gif[37] canvas=58x66 size=50x63 offset=+7+1 Background 3centisecs
treething.gif[38] canvas=58x66 size=50x63 offset=+7+1 None 3centisecs
treething.gif[39] canvas=58x66 size=52x65 offset=+1+1 Background 3centisecs
treething.gif[40] canvas=58x66 size=57x65 offset=+1+1 Background 3centisecs
treething.gif[41] canvas=58x66 size=57x65 offset=+1+1 None 3centisecs
treething.gif[42] canvas=58x66 size=53x63 offset=+1+2 Background 3centisecs
treething.gif[43] canvas=58x66 size=54x63 offset=+1+2 Background 3centisecs
treething.gif[44] canvas=58x66 size=54x65 offset=+1+0 Background 3centisecs
treething.gif[45] canvas=58x66 size=55x65 offset=+1+0 Background 3centisecs
treething.gif[46] canvas=58x66 size=56x65 offset=+1+0 None 3centisecs
treething.gif[47] canvas=58x66 size=44x54 offset=+14+10 Background 3centisecs
treething.gif[48] canvas=58x66 size=44x63 offset=+14+2 Background 3centisecs
treething.gif[49] canvas=58x66 size=44x63 offset=+14+2 Background 3centisecs
treething.gif[50] canvas=58x66 size=44x63 offset=+14+2 Background 3centisecs
treething.gif[51] canvas=58x66 size=51x63 offset=+7+2 Background 3centisecs
treething.gif[52] canvas=58x66 size=51x63 offset=+7+2 None 3centisecs
treething.gif[53] canvas=58x66 size=40x31 offset=+14+3 Background 3centisecs
treething.gif[54] canvas=58x66 size=52x55 offset=+4+2 Background 3centisecs
treething.gif[55] canvas=58x66 size=52x55 offset=+4+2 None 3centisecs
treething.gif[56] canvas=58x66 size=49x51 offset=+1+6 None 3centisecs
treething.gif[57] canvas=58x66 size=56x63 offset=+2+2 Background 3centisecs
treething.gif[58] canvas=58x66 size=56x65 offset=+2+0 None 3centisecs
treething.gif[59] canvas=58x66 size=48x64 offset=+7+1 None 3centisecs

您还可以在draw.text((0,0)...)之后将以下行插入到程序中,以获得类似的输出:
print(i,frames.dispose_extent, frames.disposal_method)

现在我需要做的就是比较这两个...

我仍然在努力查看哪里出了问题 - 我怀疑要么是:

  • 您需要向行compilation.paste(the_frame,...)添加掩码,或者
  • the_frame = frames.convert('RGBA')对您不利,因为GIF实际上是使用调色板的,转换时出了问题。

您还可以在红色背景上查看来自ImageMagick的合并帧:

magick tree.gif miff:- | magick montage -background red -geometry +5+5 -tile 12x miff:- montage.png

enter image description here


你对于转换是问题的评论似乎是正确的。如果我寻找第19个帧并执行frames.show(),它会正确地显示。我不确定如何在不使用convert的情况下正确获取拼贴中的每个帧。 - DevilGale

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