Despite its dominance on the Internet, JPG falls short when it comes to the TEXT and Line Arts. In the eyes of spectrum analyzer, those sharp angles in the TEXT and Line Arts are interpreted as high frequency components, which is the soft belly of JPG since it sacrifices high frequency components in favor of better compression ratio.

Another shortcoming of JPG is that it does not support 1 bit black and white format. But for TEXT, 1 bit is probably good enough for the legibility.

PNG, on the other hand, does a better job if the picture content comprises mostly of TEXT, since it is a lossless format and supports 1 bit black/white format.

A side by side comparison can be found at zituyuan ( http://www.zituyuan.com, Ref[1] ), this is a Chinese website that converts text to PNG format online. GFW might have to consider adding OCR to its web patrol's arsenal.


References:

[1] http://www.zituyuan.com/t2p.php?mode=8

Posted by HAx4 at 8:47 PM

0 Comments:

Post a Comment

<< Home  

       *) Grand Opening
       *) Why HAHAHAHA
       *) Stay Foolish
       *) Rabbit Hole
       *) Blotter
       *) Notebook

       *) Blotter
       *) Notebook
       *) Rabbit Hole

       *) I Love Rei
       *) TEXT2PNG
       *) China Blog List

       *) Bertrand
       *) Bruin
       *) Bulldog
       *) Hua
       *) Mas
       *) Nimrod
       *) Philewar
       *) Rodent
       *) Samuel
       *) Tom