TIFF vs JEPG
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From: Alan Meyer on 13 Apr 2006 13:17 Raphael Bustin wrote: > On 12 Apr 2006 20:12:04 -0700, "Noons" <wizofoz2k(a)yahoo.com.au> wrote: > <http://www.terrapinphoto.com/jmdavis/chrome_41_jpg.jpg> > > and here's the same as a TIF: > > <http://www.terrapinphoto.com/jmdavis/chrome_41_tif.tif> Very interesting comparison Rafe. I could not really tell the difference. I've done this test with higher compression and found that even at 10:1 compression I was not able to tell the difference under normal, or even moderately magnified viewing conditions. > www.terrapinphoto.com By the way, that's a fine website. I looked at about 40 of your photos and every one of them looked excellent. You're good at this. Alan
From: Alan Meyer on 13 Apr 2006 19:53 When I first stated that I thought JPEG would produce results as good as TIFF for practical purposes, I expected that it would ignite some controversy, but I still think that for practical purposes, for the majority of uses and the majority of users, it's true. Consider how we used film before the digital era. For example: How many of us eschewed 35mm and only used 60x60 mm (2.25 square inches) or even larger films? I bet that the vast majority, even of serious photographers, were using 35mm for most purposes, even though the amount of captured detail is 1/4 of what it is in 60mm. How many of us used films like Panatomic-X instead of films like Tri-X or T-MAX? Very few people accepted the inconvenience and expense of the slower film, even though the grain was significantly less than for the faster films. How many of us used fixed length lenses exclusively, even though the sharpness was measurably better than for zoom lenses? Most photographers bought zooms because of the lower price and ease of carrying a single lens instead of multiple lenses. Even professional photographers, depending on what branch of photography they were in, made these compromises. Photojournalists almost exclusively used 35mm cameras and fast films. National Geographic, employing some of the highest paid and best professionals in the world, primarily used 35mm slide film. Even portrait and commercial studio photographers generally used 60mm film for most shots. They did not generally use, and often didn't own, 4x5 or 8x10 cameras. Amateurs and professionals alike, both then and now, are making very good quality images that more than meet their needs using technologies that are not ultra-high end. The JPEG/TIFF issue is not exactly analogous to the examples above. The extra cost and inconvenience of TIFF is less than the extra cost and inconvenience of large cameras and/or slow films. But on the other hand, the quality differences between TIFF and JPEG are far, far less (in my view) than the quality differences between large format and 35mm film cameras, or even between high speed and low speed films. So all I'm saying is that we sometimes get carried away with technical perfection and lose sight of what we're trying to do - which is often, I would even say usually, more than achievable with JPEG image encoding. Alan
From: Roger on 14 Apr 2006 01:42 On Thu, 13 Apr 2006 00:09:10 -0400, Raphael Bustin <foo(a)bar.com> wrote: >On 12 Apr 2006 20:12:04 -0700, "Noons" <wizofoz2k(a)yahoo.com.au> wrote: > > >>but I'll darn be able to tell which one is the JPEG! > > >I doubt that, if it's a first-generation conversion from TIF, >and if it's high-quality (low-compression) JPG. > >Obviously, JPG is inappropriate for works-in-progress. > >But it can be perfectly appropriate as an archival >format, even for critical work. As archival is most likely going to be called up to restore images and we don't know to what resolution I'd not want to have to rely on first generation jpgs. True they can be canged to TIFFs with no loss but saving them again as jpg will again add more deteoriation. I routinely have to restore an image or two per month back to hard drive, but that's on a total of over 5 terabytes on-line. > >The rule is: never more than one conversion to JPG. And keep the original film "just-in-case". Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com > >Here's a 4000 dpi film scan snippet as JPG: > ><http://www.terrapinphoto.com/jmdavis/chrome_41_jpg.jpg> > >and here's the same as a TIF: > ><http://www.terrapinphoto.com/jmdavis/chrome_41_tif.tif> > > >rafe b >www.terrapinphoto.com
From: Mike Fox on 14 Apr 2006 06:52 Even at 60% of a 133 MB TIFF, it's a huge JEPG and some of my programs have to crank a long time just to open them. I'm starting to look into what's best for the progam. > >Lots of programs can do that. I use a freebie called XnView. > >Personally, I'd convert a file to high-quality JPG rather than >downsample it, but that's just me. > > >rafe b >www.terrapinphoto.com
From: Mike Fox on 14 Apr 2006 07:18
Outstanding discussions in this thread and some very good points! I'm scanning for future generations and everything hinges on a future I can't predict. How today's imaging technology will appear tomorrow is beyond me so what someone wrote to me sometime ago seems the way to go. Use the best technology (resolution and color depth) you can afford and hope that future generations transfer your work to future media and formats. |