Silicon Investor (SI) -- The First Internet Community

STOCKTALK

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor. We ask that you disable ad blocking while on Silicon Investor in the best interests of our community. If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.

Technology Stocks : WDC/Sandisk Corporation -- Ignore unavailable to you. Want to Upgrade?

To: Mike Winn who wrote (1953)	12/4/1997 11:55:00 PM
From: Gary Spiers	Read Replies (1) \| Respond to of 60323

Mike, I disagree and agree with both you and Craig<G>. Craig said: >>ordinary 35mm film can resolve about 100 lines per mm or about 3,750 x 2,500<< I think this is too low - I agree with 100 lines per mm but think no. of pixels needs to be ~ 7,500x5,000. My reasoning is that the ccd must resolve the lines so to resolve two lines you need three pixels, for three lines you need five pixels etc. ie the number of pixels required is 2xn-1 where n is the number of lines. There are no ccds currently available in this sort of size. A 24 bit image with this many pixels will occupy ~107MB uncompressed or ~10-20MB as a JPEG image (depending on compression). So Craig was right (concerned about size of image) and wrong (incorrect estimate of no. of pixels). You pointed out that this will take some considerable processing and storage (correct). Given compact flash data transfer rates of 750kB/s it would take over two minutes just to save the uncompressed image or 13 - 26 seconds to save the JPEG image. Where you were wrong was in talking about mpeg and providing the mpeg links to support your argument. Mpeg is a low resolution movie format. The processing problems arise there because they need to put up enough frames per second (and compress/expand them to fit the viewing window) to make the movie appear smooth ie use low resolution images but lots of them. Ian asked why everyone is fixating on cameras - I don't know<G>. I just answered the question as I had the data to hand as I am considering buying a digital camera this year - my darkroom eqpt. may never come out of storage:-). Personally I am much more interested in the handheld pc market and suspect that is where the bulk of sales are at the moment for flash cards. Gary