Drobe :: The archives
About Drobe | Contact | RSS | Twitter | Tech docs | Downloads | BBC Micro

Geminus gains accelerated JPEG support

By Chris Williams. Published: 24th Mar 2006, 13:58:23 | Permalink | Printable

Three times faster than RISC OS 5, says Lees

Geminus logoRendering JPEGs up to three times faster than RISC OS 5 can manage, Adrian Lees's project to overhaul the handling of JPEG images is now available. His update to Geminus means images passed to the operating system by application software are intercepted by Geminus. The speed at which these images are handled is then accelerated, and programs such as Draw can be used to scale and rotate the JPEGs. The software is compatible with Iyonix, RiscPC and A9home computers.

Publisher Neil Spellings said: "We see this release as being of great benefit to users who work with images from digital cameras, as JPEG is the preferred format in this area."

Aemulor and Geminus author Adrian said: "The main reason for developing this is that I've always been frustrated by how slowly RISC OS's SpriteExtend decodes and renders large JPEGs.

"If you have large images from digital cameras and you view them in applications like Thump, Paint, Draw, SwiftJPEG, or use them as backdrops then you'll know that it takes many seconds for a full screen JPEG to render. In fact it spends so long decoding and rendering the JPEG that audio playback will cease with apps like DigitalCD because of the way the OS is structured."

Adrian explained that when his JPEG handling code is used, the sound system and other components such as ShareFS will continue to work rather than stalling if the image decoding consumes too much processor time.

He said: "Decoding and rendering is about three times faster than the RISC OS 5 SpriteExtend module. It's also faster than the RISC OS 4, Select and Adjust SpriteExtend module but the difference is not as great because these versions already have faster JPEG decoding."

The enhanced JPEG handling was first previewed in February at the South West show. Open source graphics applications OpenVector, OpenGridPro and DrawPlus have also been updated by Adrian to make use of the JPEG acceleration and also use RISC OS Select's Image File Convert plugins.


Spellings Software website

Previous: News in brief
Next: Thank Acorn for embedded tech growth says Oregan exec


Viewing threaded comments | View comments unthreaded, listed by date | Skip to the end

This is definitely a good move to sell (versions of) Geminus to RPC owners, so adding the ability to sell to an extra audience.

I have to say, it's not the most exciting sounding development though, compared to screen rotation or driving multiple graphics cards independently (which you can get on an Iyonix via similarly priced Geminus versions). I'm sure a lot of work went into it though - and if it results in a more robust spriteextend module that lets me view JPEGs I can't currently on RISC OS, then it's definitely worth my money.

 is a RISC OS Userninja on 24/3/06 5:17PM
[ Reply | Permalink | Report ]

I actually think that this is quite exciting. One of my major uses of the Iyonix is processing and viewing digital photos and a factor of three in speed is not to be sniffed at. OTOH, I have no use for screen rotation though I agree that it is a much more dramatic function.

Sadly, I doubt that the rotation code will get very much use since applications will not be able to rely on it being present so will have to do their own thing (as many, including OHP, already do).

 is a RISC OS UserTonyStill on 24/3/06 9:28PM
[ Reply | Permalink | Report ]

I can rotate JPEG files in !Draw nice !! But faster JPEG plotting ? I can't see it (A9Home 1600x1200 16M)

I use the demo version 1.30

 is a RISC OS UserEasyKees on 26/3/06 2:53PM
[ Reply | Permalink | Report ]

Great software and needed. I bought a copy but it seems to kill !Jcut :-( a vital part of my image manipulation software. Has anyone else found the same?

 is a RISC OS Userrmac on 26/3/06 3:48PM
[ Reply | Permalink | Report ]

rmac Yes have found the same problem with JCut. Posted a message at support.spellings.net.

DPlngScan is seems much quicker however, haven't tried much other software at the moment besides Photodesk (which also seemed quick rather like Paint on the Iyonix opening up a large sprite).

 is a RISC OS Userblahsnr on 26/3/06 5:31PM
[ Reply | Permalink | Report ]

I've resolved the problem with JCut, see the support forums for more info. An update to Geminus will be available shortly, once I can be reasonably confident that any other problems identified with the first release have been resolved.

 is a RISC OS Useradrianl on 27/3/06 12:41AM
[ Reply | Permalink | Report ]

PCs are not terribly quick at processing jpegs either, but a lot of the viewers hide this from the user by caching the next image whilst the user is looking at the current image. Shame that Thump is no longer maintained.

 is a RISC OS Userjeffd on 29/3/06 10:45AM
[ Reply | Permalink | Report ]

The update, version 1.31, is now on the site. See the 'My software' page if you've already downloaded a copy.

 is a RISC OS Useradrianl on 30/3/06 10:06AM
[ Reply | Permalink | Report ]

adrianl 1.31 does indeed fix the problems with JCut. Many thanks!

 is a RISC OS Userblahsnr on 1/4/06 10:35AM
[ Reply | Permalink | Report ]

Please login before posting a comment. Use the form on the right to do so or create a free account.

Search the archives

Today's featured article

  • Voice-over-IP on RISC OS: What's involved?
    A client is possible once someone with the brains is talked into making it
     23 comments, latest by JGZimmerle on 7/11/05 5:06PM. Published: 30 Oct 2005

  • Random article

  • Family tree software in bug fix update
    Ancestor Plus version 3.08 released online
     Discuss this. Published: 6 Apr 2007

  • Useful links

    News and media:

    Top developers:
    RISCOS LtdRISC OS OpenMW SoftwareR-CompAdvantage SixVirtualAcorn

    CJE MicrosAPDLCastlea4X-AmpleLiquid SiliconWebmonster


    RISCOS.org.ukRISCOS.orgRISCOS.infoFilebaseChris Why's Acorn/RISC OS collectionNetSurf

    Non-RISC OS:
    The RegisterThe InquirerApple InsiderBBC NewsSky NewsGoogle Newsxkcddiodesign

    © 1999-2009 The Drobe Team. Some rights reserved, click here for more information
    Powered by MiniDrobeCMS, based on J4U | Statistics
    "Don't suppose you could remove that article, just for a few hours?"
    Page generated in 0.098 seconds.