Strange gif background color

[retsyo]

I am using PILLOW 4.2.1-py36_0 which is updated by conda from Python 3.6.0 |Anaconda custom (64-bit)| (default, Dec 23 2016, 11:57:41) [MSC v.1900 64 bit (AMD64)] on win32

I found sometimes the produced gif has strange background.

1. I only find this with Stcaiyun.ttf
2. Even for Stcaiyun.ttf, sometimes the gif is ok
3. The framexx.png is ok

import random
from PIL import Image, ImageDraw, ImageFont

frames = []
for frame in range(10):
    img = Image.new(size=(320, 200), mode='RGB', color='white')
    
    drw = ImageDraw.Draw(img)
    text = '% 2i' % frame
    font = ImageFont.truetype(r'd:\WINDOWS\Fonts\STCAIYUN.TTF', 80)
    #~ font = ImageFont.truetype(r'd:\WINDOWS\Fonts\Stfangso.ttf', 80)
    #~ font = ImageFont.truetype(r'd:\WINDOWS\Fonts\times.TTF', 80)
    #~ font = ImageFont.truetype(r'3Dkirieji.ttf', 80)
    x, y=random.randint(60,250), random.randint(20,100)
    color = random.choice(['red', 'green', 'blue', (0, 127, 127)])
    drw.text((x, y), text, font=font, fill=color)
    img.save('frame%02i.png' % frame)
    frames.append(img)
    
frames[0].save('out.gif', save_all=True, append_images=frames[1:], duration=300, loop=True, optimize=True)

I am sorry I cannot upload STCAIYUN.TTF since it is some huge

out.zip

[wiredfool]

This looks similar to the other GIF palette issues, #1717, #1987, etc. And if not similar, it's still tied up in it.

It's possible that the optimize flag is throwing it off, compressing all the colors in the palettes to the 0,1 indexes. And optimize is not doing anything for you here.

(Aside -- Optimize is a horrible name, because everyone wants optimization. But it's effect is removing unused colors from the palette, saving a max of 760 bytes/frame in the best case (palette entries at 0,255), at the cost of visiting every pixel 5 times and making 3 extra copies of the image in memory)

[retsyo]

it seems that optimize=False produces right gif

[radarhere]

Installing Pillow 4.2.1 from source, I'm unable to replicate.