Actually, there are ways to do things like this. It is very common for applications to read every 8th pixel of a JPEG to make a thumbnail, or display a rough image quickly.
Due to the way JPEG compression works, by doing DCT based compression on 8x8 blocks, a value for each 8th pixel is actually present. This is commonly called the "DC component" for the block. It is usually in YUV colourspace, of course, so a conversion needs to be done to RGB, but thats trivial. Love, Light and Peace, - Peter Loveday Director of Development, eyeon Software ----- Original Message ----- From: "Herb Chong" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Saturday, April 03, 2004 9:40 AM Subject: Re: New *ist D review - Imaging Resource > JPEG compresses data. you don't know what the nth pixel is until you > decompress enough of the file to find it. some other formats do row level > lossless compression, so you can figure out which row to decompress, but > that is all. > > Herb.... > ----- Original Message ----- > From: "vr" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Friday, April 02, 2004 4:59 AM > Subject: Re: New *ist D review - Imaging Resource > > > > how is that? > > you can give an order to address and read every 4th pixel from file.. > > > > what do you think modern databases work like where ypou can get desired > > bits from huge file in seconds if the file is indexed?? > > > > though to be faster or more reasonable compared to readin everything the > > gap should not be every 4th pixel, but much wider.. > > >
