From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266217AbUH1RLY (ORCPT ); Sat, 28 Aug 2004 13:11:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266674AbUH1RLY (ORCPT ); Sat, 28 Aug 2004 13:11:24 -0400 Received: from viper.oldcity.dca.net ([216.158.38.4]:45220 "HELO viper.oldcity.dca.net") by vger.kernel.org with SMTP id S266217AbUH1RLW (ORCPT ); Sat, 28 Aug 2004 13:11:22 -0400 Subject: Re: reverse engineering pwcx From: Lee Revell To: Albert Cahalan Cc: linux-kernel mailing list , clemtaylor@comcast.net, qg@biodome.org, rogers@isi.edu In-Reply-To: <1093712176.431.6806.camel@cube> References: <1093709838.434.6797.camel@cube> <1093710358.8611.22.camel@krustophenia.net> <1093712176.431.6806.camel@cube> Content-Type: text/plain Message-Id: <1093713088.8611.30.camel@krustophenia.net> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 Date: Sat, 28 Aug 2004 13:11:28 -0400 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 2004-08-28 at 12:56, Albert Cahalan wrote: > On Sat, 2004-08-28 at 12:25, Lee Revell wrote: > > On Sat, 2004-08-28 at 12:17, Albert Cahalan wrote: > >> [somebody] > > > > > The LavaRnd guys examined the pixels on the actual > > > > CCD chip. It's 160x120. The 'decompression' is > > > > just interpolation. > > > > > > Don't put much faith in the 160x120 number. Suppose > > > that the chip is in a Bayer pattern, with 160x120 > > > of those. Well, how many pixels is that? Who knows. > > > You'd sort of have 160x120, but with double the > > > green data. Since green carries most of the luminance > > > information, producing a larger image is reasonable. > > > > Right, as someone else pointed out, this is wrong. > > > > How do you account for the Slashdot poster's assertion that it's > > physically impossible to cram 640 x 480 worth of data down a USB 1.1 > > pipe? > > 640x480 uncompressed 24-bit RGB? It doesn't matter. > > The suggestion of a 4x4 JPEG-like transform seems > pretty reasonable. I'd like to see that whitepaper. > This still can't be called 'True 640 x 480' by any reasonable standard. Philips' marketing claims exactly this. So far I have not seen any evididence to refute QuantumG's original assertion that the reason everyone in the know is being so tight-lipped is that releasing source code would prove Philips and/or Logitech guilty of false advertising. Lee