150k file limit increase PLEASE - DPChallenge Forums

11/16/2004 03:53:37 PM · #26

Originally posted by faidoi:

Does a higher file size help the dSLR users more then it would for people still using point & shoot, prosumers, etc or would it still be an even playing field?

No, the opposite is true. DSLR cameras produce soft, film like images with low noise, that lend themselves to better compression. The more noise, lines and dots in a picture the worst the compression. Most jpeg compressors have a blur function for this very reason. The over sharp, and noisy images out of point and shoot cameras need more bits because they have more 'bad' information that takes up compression space. The same is true for online music files, the more background noise the worst the compression.

Canon EF 70-200mm f/2.8L IS USM

11/16/2004 03:53:59 PM · #27

error

Message edited by author 2004-11-16 15:54:30.

EddyG

Canon EOS-1D Mark II

11/16/2004 03:54:31 PM · #28

This image:

needed to be saved at JPEG quality 50 in the "Save For Web" dialog to get it under 150K. It is one of the worst types of images for JPEG compression.

That being said, I did not receive any "the JPEG artifacts totally ruined this photo". And this was at quality 50!

150K is plenty.

(And I would be opposed to some "on the fly" recompression scheme, because it takes one more aspect of image quality out of the hands of the photographer. Have you ever tried surfing with one of those "dialup accelerators"? That is exactly what they do -- recompress the images so they download faster -- and photos look horrible.)

Message edited by author 2004-11-16 15:54:45.

Nikon AF-S DX NIKKOR 18-200mm f/3.5-5.6G ED VR II

11/16/2004 04:05:07 PM · #29

Lets say you have a 30MB photoshop file. Most 6-8 MP cameras produce files this big from raw 16bit originals. Now to hit 150KB, your going to compress the image by 200 times. To hit 250KB it would be 120 times, still a huge compression factor from the original. 640 @ 150KB is a great size for the web. I buy stock photos from 480x320 @ 20KB thumbnails costing upward of $200 each. Can we just put this whole issue to rest?

BobsterLobster

Fujifilm FinePix S3 Pro

11/16/2004 04:15:19 PM · #30

Originally posted by Pedro:

so you're telling me you can see compression artifacts in this photo?

it's only 128KB, so it can't possibly be anything but crap.

I've seen this image at full res on my computer, and it's marginally better than this compressed one. i don't believe for a second that we need more than 150KB.

Of course I'd use bigger images if it were all about me, but it's not.

This photo has large areas of flat colour with no detail. Not really a good example.

Check out these examples of jpeg compression artifacting:

50kb

57kb

105kb

98kb

91kb

They all show noticable jpeg artifacting, and I just chose them quickly from my portfolio.
I'd love to save them all at 150kb, but just don't have the room. C'mon, give us some extra room please!!! We'll pay!!!

Nikon AF Nikkor 50mm f/1.8D

11/16/2004 04:39:17 PM · #31

Originally posted by scalvert:

So it's settled then. From now on DPC will be a Canon-only site. ;-)

Good one. BTW what is the flash sync on your 300?

deapee

Kodak V803

11/16/2004 04:43:46 PM · #32

What do you guys mean when you say save it at 80 or 50 or whatever? In photoshop, I just get an option of 1 through 12, 12 being the highest. I save most of mine at 10 so they're under the 150 limit. If I'm submitting to stock or for prints, I save them at 12, obviously.

Canon EF 70-200mm f/4.0L USM

11/16/2004 04:48:27 PM · #33

Originally posted by Pedro:

so you're telling me you can see compression artifacts in this photo?

it's only 128KB, so it can't possibly be anything but crap.

You are being a little literal aren't you? Your photo doen't contain alot that would make it large does it? The colors are most oranges & yellows with alot of continous tones. To over simplfy JPG compresson "describes" the image in mathamatical terms. Instead of indivdually describing each pixel, it can say the next 30 pixels are this color yellow. 128k might be a perfect balance of quality to compression for your image, but another image at the same resoultion might look like "crap"

BTW GREAT image;-)

RHoldenSr

Canon EOS-5D

11/16/2004 04:50:26 PM · #34

In Photoshop "File" + "Save For Web".

In the new window open the "Optimize Menu"
(The small arrow to the right of the drop down "Preset Menu")

Select "Optimize To File Size"

Simply enter the size you would like the image to be i.e. 50k or etc.

Then save the file.

Edit: Added quote.

Originally posted by deapee:

Message edited by author 2004-11-16 16:52:03.

scalvert

Canon EOS-5D Mark III

Canon EF 24-105mm f/4.0L IS

11/16/2004 04:51:52 PM · #35

Originally posted by hyperfocal:

...what is the flash sync on your 300?

It's what allows you to coordinate the shutter with external flash units. ;-P

BTW- has anybody noticed that the highest-scoring page for the D70 looks remarkably like Librodo's personal portfolio?

Nikon AF Nikkor 50mm f/1.8D

11/16/2004 04:56:59 PM · #36

Originally posted by deapee:

Your using the save or save as.. command which, depending how you set up your file handling in the preferences, will posibily save either thumbnails or meta information or both. Both of which increases the file size. Mac users will also have in the preferences a save PC thumbnail also.

Use the save for web command and you will get a dialog box with the settings we are talking about. The command also has several other features and info useful for file saving.

Note: don't use the image resize option there unless you are changing the resoultion by less than 50%. i would save the original file, then resize it, then use the save to web command.

deapee

Kodak V803

11/16/2004 04:59:36 PM · #37

oh i see. So I should use Save for Web instead of file, save as. hrmm...what would I use the save as for? Just for saving PSD's I would imagine? Thanks for being patient.

11/16/2004 05:17:29 PM · #38

Originally posted by mk:

Hyperfocal, can you post examples of a photo that's under 150 and a copy of the same that's over so that we can see the difference?

All three photos have the same tonality (1/2 white and 1/2 black) , 100% quality, and 640x480 resoultion , but the file sizes are as follows...
Just Black and white = 4k
Grad = 28k
Checks = 280k

kyebosh

Canon EOS-20D

Canon EF 80-200 f/2.8L

11/16/2004 05:21:29 PM · #39

if the compressor coulda recognized the patturn it woulda saved a lot space.

scottwilson

Canon EOS-350D Rebel XT

Canon EF 28mm f/2.8

11/16/2004 05:30:49 PM · #40

I find that 150K is normally more then enough for the photos I post.
This photo is right at about 100K and the comments were on how clean the image was.

There are some jpg artifacts in the image but you have to blow it up to really see them.

I have not run into many cases where I felt going over 150K would have made my photo look better.

I do feel that we should give the people with dial-up as much of a break as we can. I will compress my images down until they just start to show some reduction in quality then back off on the compression just a bit.

A 640 x 640 image that uses 150K comes in at just under 3 bits / pixel, this is not normally considered excessive compression.

Canon EF 100mm f/2.8 Macro

11/16/2004 05:33:00 PM · #41

Originally posted by kyebosh:

if the compressor coulda recognized the patturn it woulda saved a lot space.

thanks you just helped me make my point. Photographs are totaly random with no pattern so compression scemes are inefficent on photos.

scottwilson

Canon EOS-350D Rebel XT

Canon EF 28mm f/2.8

11/16/2004 05:35:45 PM · #42

Originally posted by hyperfocal:

Originally posted by kyebosh:
if the compressor coulda recognized the patturn it woulda saved a lot space.

thanks you just helped me make my point. Photographs are totaly random with no pattern so compression scemes are inefficent on photos.

Does this really look that bad

This is the photo compressed to 97K.
edit to say you have to push the thumbnail to see the full image

Message edited by author 2004-11-16 17:36:48.

umbris

Canon EOS-20D

11/16/2004 05:47:52 PM · #43

There is software product that I have used for about 7 years that is very useful for creating high quality jpgs. It's called ThumbsPlus //cerious.com. It allows you to independently control the quality, sub sampling and smoothness. I consistently get 95%-97% quality with 1:1 sub sampling for my submissions to DPC. The software is about the cost of 1 month of broadband service and well worth it. I highly recommend it.

bledford

Canon EOS-300D Rebel

Canon EF-S 18-55mm f/3.5-5.6

11/16/2004 06:04:26 PM · #44

Originally posted by scottwilson:

Does this really look that bad

Oooooh, burn!

EddyG

Canon EOS-1D Mark II

Canon EF 70-200mm f/2.8L IS USM

11/16/2004 06:06:34 PM · #45

Originally posted by hyperfocal:

Photographs are totaly random with no pattern so compression scemes are inefficent on photos.

Except that the JPEG format is specifically designed to compress photographs -- in other words, continuous tone images like what you see on DPC. It is (by its very nature) not designed to compress "line art" like your "pattern" example very well (but still does an admirable job if you make it do it).

150K is a huge file size for a 640px DPC challenge entry.

Are you obsessed with saving your images with "Quality = 100"? That basically means "don't compress my image at all", and that's not the point of JPEG. The JPEG format (and its complex encoding algorithms) is designed to preserve continuous-tone photographic image integrity as the file size is reduced. Obviously there are trade-offs as the compression level increases, but for the most part, it does an amazing job.

Message edited by author 2004-11-16 18:12:16.

11/16/2004 06:26:44 PM · #46

Originally posted by EddyG:

I know the jpeg compression sceme was created to compress photos (cont. tone images), but that doesn't mean that it is an efficient means of doing so. How many times has a graphic artist created from scratch an image that contains millions of colors? Seldom, but even a "snap shot" of grandma contains millions of colors. In college I studied compression algrathims at a time when compression was very important (late 80's to eary 90s), and the difficulties of compression "complicated images" are numberous.

As far as being obsessed with saving at 100%, yes I am totally obsessed with quality. 100% quality compresses the image by at least 2:1 ratio most times ususally closer to 4:1. (Just for example I compressed a 17.4mb file to 100% quality jpg and it resulted in a 4mb file).

(BTW off topic but on subject) I'm also obsessed with the same issue in music. i think most CDs sound like "crap" compared to vinyl thanks to freq. compression. Needless to say mp3s which destroy quality music thru compression, are barley worth listening to.

kyebosh

Canon EOS-20D

Canon EF 80-200 f/2.8L

11/16/2004 06:44:25 PM · #47

To relate your audio to photography...

First look at the purpose of the site. It's to show a small version of the work of what we did so that many can view it easily. Now if that's all it has to do, why make it so complex? Take for example the telephone. The actual quality of a telephone as compaired to a CD is aweful. However, would you argue that the telephone is not good enough for it's purpose? Can you not understand the other person speaking if the quality isn't the same as a CD?

11/16/2004 06:55:00 PM · #48

The checkerboard pattern would look good under gif compression from the original file with only 2 colors @ about 30K. Gif is meant to handle that picture type. Jpeg is meant for tonal values. A saw and a hammer do two very different things to wood. We are talking about tools, and for 99% of the images on this site, 150KB is just fine. If you have a problem with storage space take that up some where else please.