optimized image...
** Processing: ./tw.png
35x80 pixels, 4x8 bits/pixel, RGB+alpha
Reducing image to 8 bits/pixel, 42 colors (40 transparent) in palette
Input IDAT size = 718 bytes
Input file size = 1626 bytes

Trying:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 462

Selecting parameters:
  zc = 9  zm = 8  zs = 0  f = 0		IDAT size = 462

Output IDAT size = 462 bytes (256 bytes decrease)
Output file size = 1560 bytes (66 bytes = 4.06% decrease)