Actually the question was whether zipping would help them...but copying the data into RAM, zipping it, and copying it back to the USB drive before copying to an internal drive kind of defeats the purpose...and would take more time that just copying.
That aside, my experience over the past 20 years with image compression is significantly different. That's why I went into my mini discourse...wanting to point out that a generalization didn't really work when image formats vary significantly in how they respond to zip compression. I see significantly higher compression than you indicate on uncompressed formats. Generally around 1/3 of the original size, so comparable to the Word documents you mentioned. Since compression rates can vary so widely with different formats, I think a discussion of the differences was warranted...especially since the discussion was around a particular format, TIFF, which is most often uncompressed, or perhaps run length compressed with palette color images. Darin. ----- Original Message ----- From: "Michael Graveen" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, October 20, 2004 11:16 PM Subject: Re: [Declude.JunkMail] OT - Copying 200,000 plus files I think the question was about zipping graphic files, which as a general rule, don't get much smaller after they're zipped (as compared to text files, etc.). I wasn't taking about the compression contained in a particular graphic format. I get about 15%-25% reduction zipping the "uncompressed" BMP file vs about 70% from a Word doc (using the stock Winzip settings). I should have been clearer in my first response. Mike At 06:43 PM 10/20/2004, you wrote: >Huh? The logic flaw in trying to zip first, then copy aside (since the file >would have to first be copied into RAM, then zipped, then stored back onto >the USB drive...better just to copy)... uncompressed TIFFs (TIFFs have had >an option for LZW compression since the mid 90s) compress pretty well as >they contain raw raster data, as do BMPs and many other uncompressed >formats. > >If you're referring to JPEGs and GIFs, that's because they are already >compressed. JPEGs have built-in lossy compression, but high quality JPEGs >(low compression) can still see decent compression, and GIFs are already LZW >compressed, which means more LZW compression generally doesn't yield much. > >So, it depends on the type of image, but TIFFs are generally uncompressed >these days due to the LZW copyright fiasco, or may have run-length encoding >which still compresses reasonably well with LZW. > >Darin. > > >----- Original Message ----- >From: "Michael Graveen" <[EMAIL PROTECTED]> >To: <[EMAIL PROTECTED]> >Sent: Wednesday, October 20, 2004 6:11 PM >Subject: Re: [Declude.JunkMail] OT - Copying 200,000 plus files > > >Graphic files as a general rule don't compress well. > >Mike > >At 03:26 PM 10/20/2004, you wrote: > >Jeff Pereira wrote: > >>What's killing me is not so much the amount of data, but the fact that > >>there are so many small files. I'm gonna have to try XCOPY on the > >>next folder and see how that works. > > > >I can't remember but do TIFF files compress well? Might be worth it to > >ZIP them and copy that over. > > > >Jim > >--- >[This E-mail scanned for viruses by Declude Virus] > >--- >[This E-mail was scanned for viruses by Declude Virus >(http://www.declude.com)] > >--- >This E-mail came from the Declude.JunkMail mailing list. To >unsubscribe, just send an E-mail to [EMAIL PROTECTED], and >type "unsubscribe Declude.JunkMail". The archives can be found >at http://www.mail-archive.com. > >--- >[This E-mail was scanned for viruses by Declude Virus >(http://www.declude.com)] > >--- >This E-mail came from the Declude.JunkMail mailing list. To >unsubscribe, just send an E-mail to [EMAIL PROTECTED], and >type "unsubscribe Declude.JunkMail". The archives can be found >at http://www.mail-archive.com. >--- >[This E-mail scanned for viruses by Declude Virus] --- [This E-mail scanned for viruses by Declude Virus] --- [This E-mail was scanned for viruses by Declude Virus (http://www.declude.com)] --- This E-mail came from the Declude.JunkMail mailing list. To unsubscribe, just send an E-mail to [EMAIL PROTECTED], and type "unsubscribe Declude.JunkMail". The archives can be found at http://www.mail-archive.com. --- [This E-mail was scanned for viruses by Declude Virus (http://www.declude.com)] --- This E-mail came from the Declude.JunkMail mailing list. To unsubscribe, just send an E-mail to [EMAIL PROTECTED], and type "unsubscribe Declude.JunkMail". The archives can be found at http://www.mail-archive.com.
