Changes between Initial Version and Version 1 of libpipi/oric Tweet

Timestamp:

09/28/2008 11:28:06 PM (16 years ago)

Author:

Sam Hocevar

Comment:

move the relevant img2oric information to a libpipi subpage

libpipi/oric

@@ +1 @@
+[[Image(source:www/img2oric/real-oric.jpeg,align=right)]]
+= Oric Atmos graphics using libpipi =
+
+[wiki:libpipi] can load and save images in the Oric screen format. The [http://www.defence-force.org/computing/oric/gallery/index.htm Oric screen format] is one of the most twisted standards and very little artwork exists for this vintage computer. It was therefore the perfect challenge for the Caca Labs image processing team.
+
+The graphical part of the Oric screen has 240×200 pixels and can only display 8 different colours (black, blue, red, green, cyan, magenta, yellow and white). Each horizontal group of 6 pixels can only use two different colours: the foreground and the background colours. The background ''or'' the foreground colour may also be changed (one at a time), but while doing so the next 6 pixels cannot be chosen: they will use the background colour instead. Finally, a special bit may be activated to display the current group of pixels in reverse video.
+
+[wiki:libpipi] is pretty slow: around 2 minutes to process an image on a modern computer at full quality. It is certainly possible to make it run faster, but I am not aware of trivial ways to do so, except by reducing the computation depth (hence reducing the quality).
+
+== Downloads ==
+
+There used to be a program called `img2oric` to do this task, but [wiki:libpipi]’s `pipi` utility is now far more powerful.
+
+Windows executable (28 Sep 2008 snapshot): [/files/img2oric/pipi.exe pipi.exe].
+
+For those interested, the relevant source code is in [/browser/libpipi/trunk/pipi/codec/oric.c oric.c].
+
+== Examples ==
+
+Convert an Oric `.tap` file into a BMP:
+
+{{{
+pipi screen.tap -o image.bmp
+}}}
+
+Convert a BMP file into an Oric `.tap` file:
+
+{{{
+pipi image.bmp -o screen.tap
+}}}
+
+Convert a BMP file into an Oric `.tap` file, then reopen the `.tap` file and save it as another BMP:
+
+{{{
+pipi image.bmp -o screen.tap screen.tap -o screen.bmp
+}}}
+
+Open a BMP file, convert it to linear colour space (gamma = 1.0), apply a 2×2 Gaussian blur filter and save it into an Oric `.tap` file:
+
+{{{
+pipi image.bmp --gamma 1 --gaussian 2 -o screen.tap
+}}}
+
+== Screenshots ==
+
+These images show how [wiki:libpipi] performs. The results may not seem terribly clean, but they are probably better than anything that has been seen so far on an Oric computer.
+
+These first 4 images show the results on the same images than the ones on Dbug’s [http://www.defence-force.org/computing/oric/coding/annexe_3/pictconv/ PictConv] website, to illustrate the improvements over the traditional RGB separation technique.
+
+[[Image(source:www/img2oric/buffy.png)]] [[Image(source:www/img2oric/output-buffy.png)]] [[Image(source:www/img2oric/mire.png)]] [[Image(source:www/img2oric/output-mire.png)]]
+
+[[Image(source:www/img2oric/dog.png)]] [[Image(source:www/img2oric/output-dog.png)]] [[Image(source:www/img2oric/lena.png)]] [[Image(source:www/img2oric/output-lena.png)]]
+
+The following images show [wiki:libpipi]’s results with grayscale
+images and cartoon images.
+
+[[Image(source:www/img2oric/bufbw.png)]] [[Image(source:www/img2oric/output-bufbw.png)]] [[Image(source:www/img2oric/homer.png)]] [[Image(source:www/img2oric/output-homer.png)]]
+
+The following images use real Oric artwork, taken from the Buggy Boy and the VIP 4 demos: they are almost pixel-perfect.
+
+[[Image(source:www/img2oric/bb.png)]] [[Image(source:www/img2oric/output-bb.png)]] [[Image(source:www/img2oric/eatme.png)]] [[Image(source:www/img2oric/output-eatme.png)]]
+
+And finally, this is an animation whose frames were converted to Oric colours using [wiki:libpipi]:
+
+[[Image(source:www/img2oric/bear.gif)]] [[Image(source:www/img2oric/output-bear.gif)]]
+
+== Credits ==
+
+The libpipi Oric codec was written by Sam Hocevar. Thanks to Jean-Yves Lamoureux, Mickaël Pointier, Robert Chéramy, André Chéramy and Fabrice Frances for their help, their work and the information they provided.