Where's Waldo? At the Circus
Technical Analysis and Fan Page

Content for everyone

Technical stuff

Links

(German or English)

ART file variants

ART FILES BY IMAGINATION PILOTS
Technical overview by Daniel Marschall						15 Feb 2018


		VERSION 1.x (16-bit era, "IPE16")
		=================================

Version 1.0	For game: "Blown Away" (1994)
		* File signature "Art" + 20 NUL bytes
		* Image names up to 23 characters
		  (unsure if the 23th byte must be a zero terminator)
		* LZW implementation: GIF standard implementation
		  - variable code length between 9 and 12 bits
		  - clear code (256)
		  - end code (257)
		* Pictures can only be 8-bit
		* Each picture can either be LZW compressed (code "P")
		  or uncompressed (code "p", lower case)
		* Decompressed/raw data: Top-down pixel data
		* Attached: Optional palette (R,G,B), uncompressed.
		  (Sprites usually do not have a palette, so the game
		   will use the palette of the parent picture)

Version 1.1	For games: "Panic in the Park" (1995)
		           "Where's Waldo? At the Circus" (1995)
		* Codes for compression/raw are now "Q" and "q" instead of
                  "P" and "p"
		* Each picture has now a relative X- and Y-offsets for 'fine-tuning'.
		  These offsets cannot be negative, though.

		VERSION 2.x (32-bit era, "IPE32")
		=================================

Version 2.0	For games: "Where's Waldo? Exploring Geography" (1996)
		           "Eraser Turnabout" (1997)
		           "Virtual K'Nex" (1998)
		* File signature "ART_DATA"
		* Image names up to 8 characters;
		  no zero termination required after the 8 characters.
		* LZW implementation by Mark R. Nelson and Shawn M. Regan
		  - variable code length between 9 and 13 bits
		  - clear code (256)
		  - end code (257)
		* Pictures are divided into chunks. Each chunk can be compressed or
		  uncompressed. Limitations:
		  - Each compressed chunk (except the last one) must decode into
		    exactly 16382 (0x3FFE) bytes of uncompressed data.
		  - The size of the compressed data of a chunk must not exceed the
		    size of the original uncompressed data.
		* The size of each chunk (raw or compressed) is limited
		  to max. 32767 Bytes (0x7FFF).
		* Decompressed/raw data: Windows Bitmap (without file header);
		  therefore, theoretically every color depth/compression/etc. can be used.
		  For 8-bit pictures, the palette is included in the Bitmap.
		* Re-using of parent palette is not possible.

© 2024 Daniel Marschall - - www.daniel-marschall.de

Please also see my pages for other Imagination Pilots games:
Blown Away | Panic in the Park | Waldo at the Circus | Waldo Exploring Geography | Eraser Turnabout | Virtual K'Nex