> adobe | postscript | pdf <
// Ascii85 - Adobe's Base85 encoding for PostScript and PDF
Adobe Standard
Official encoding used in PostScript and PDF documents worldwide.
25% Overhead
More efficient than Base64 with only ~25% size increase.
Zero Compression
Special 'z' character represents four zero bytes efficiently.
>> technical info
How Ascii85 Works:
Ascii85 encodes 4 bytes into 5 printable ASCII characters (33-117). It uses special encoding for all-zero groups ('z') and includes <~ ~> delimiters in Adobe's implementation.
Example:
"Hello" → <~87cURD]i,"~>
Why Use Ascii85:
- >Adobe PostScript/PDF standard
- >25% overhead vs 33% for Base64
- >Efficient zero compression
- >Printable ASCII output
- >Wide tool support
>> frequently asked questions
What is Ascii85 encoding?
Ascii85 (also called Base85) is Adobe's binary-to-text encoding scheme used in PostScript and PDF files. It encodes binary data using 85 printable ASCII characters.
What are the <~ ~> delimiters?
The <~ and ~> delimiters mark the beginning and end of Ascii85-encoded data in Adobe's implementation. They help parsers identify encoded sections in PostScript/PDF files.
How does Ascii85 differ from Z85?
While both are Base85 variants, Ascii85 uses a different character set and includes whitespace. Z85 is optimized for source code, while Ascii85 is optimized for PostScript/PDF.
What does the 'z' character mean?
The 'z' character is a special compression feature in Ascii85. It represents four consecutive zero bytes, making the encoding more efficient for data with many zeros.