Why do images change so much when uploaded?

Tamron AF 28-300mm f/3.5-6.3 XR Di LD Aspherical IF for Canon

06/11/2005 08:45:44 AM · #1

I am looking at my darkness submission side by side - left is still on my hard drive ready to be submitted, right is after submission on preview page. The one still on my hd is crisp, clear, has the right brightness, etc. The one on the preview page looks much darker, distorted, noisey. What is the difference?

If I look at the photo unsubmittd in my browser it looks the same as it does in my editor. It is only the submitted image that looks different.

SDW

Canon EOS-60D

06/11/2005 08:53:30 AM · #2

The only thing I can say is when you upload [submit] it has to save on DPC server. One more save as jpg causes picture distortion, artifacts, loss of contrast and brightness, etc. So I would guess that It is because it had to save it once again as jpg.

EDIT: to see if that is true. Make a copy of your unsubmitted file and run it trough a "save as" again and see if it ends up looking close to what your submitted file looks like.

Message edited by author 2005-06-11 08:55:41.

shutterbugKD

Olympus D-560Z

06/11/2005 08:59:30 AM · #3

well if that's true, should i be burning my pictures onto a cd in another format? my camera takes them in jpg...

Artifacts

Canon EOS-5D Mark II

Canon EF 24-105mm f/4.0L IS

06/11/2005 09:33:53 AM · #4

You didn't say, but I'm guessing your the colors look washed out on DPC.

Check the color space setting you are saving your image under for DPC. If it is "Adobe RGB (1998)" then that is the problem. Images should always be saved as sRGB for the web. That is the color space used to display images. It has a smaller color space than Adobe RGB so if it is saved under Adobe's color space then fewer of the colors can be displayed. That can explain why it looks different on your computer from the web.

This problem is solved by changing the color space to sRGB before saving the image for the web.

Message edited by author 2005-06-11 09:35:00.

PaulMdx

Canon EOS-1D

Canon EF 70-200mm f/2.8L USM

06/11/2005 09:42:14 AM · #5

Originally posted by SDW65:

when you upload [submit] it has to save on DPC server.

This only makes a binary copy of the file, it doesn't have to read in the jpeg data and resave it. I seem to remember the DPC server does make some modifications to the file, but that is only the header.

Ed: Grammar

Message edited by author 2005-06-11 09:43:02.

amber

Canon EOS-300D Rebel

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

06/11/2005 09:48:48 AM · #6

Look in the Learn section for a great tutorial on how to treat your images for DPC;)

Olympus 50-200mm f/2.8-3.5 ED Zuiko Digital

06/11/2005 09:52:14 AM · #7

Originally posted by amber:

Look in the Learn section for a great tutorial on how to treat your images for DPC;)

I have - it is written for PhotoShop - I don't use PhotoShop.

petrakka

06/11/2005 09:53:20 AM · #8

make sure you 'save for web' to get the most out of your file

twm122

Olympus E-3

06/11/2005 09:58:05 AM · #9

I use PS, I save for web and I use the highest optimizing settings to still stay with in the 150kb limit. My images still do not look as sharp as they do when I open my edited file on my hard drive. I can even just save as and still have a sharp image, but when I got o optimize it becomes less sharp. Why? I guess is my question, since this thread already adresses that issue.

Canon EF 28-135mm f/3.5-5.6 IS USM

06/11/2005 10:02:36 AM · #10

Thanks for the suggestions but they all assume someone is using PhotoShop.

justine

Canon EOS-50D

06/11/2005 10:05:26 AM · #11

Originally posted by Alienyst:

Thanks for the suggestions but they all assume someone is using PhotoShop.

What do you use?

Canon 12x IS USM (S3 IS built-in Lens) -- 36-432mm (35mm EQ)

06/11/2005 10:07:19 AM · #12

Originally posted by Alienyst:

Thanks for the suggestions but they all assume someone is using PhotoShop.

Most editing programs will have these same settings though, they just call them by different names. Someplace there will be some settings or preferences having to do with color space or profiles.

gusto

Canon EOS-7D

Sigma 50-500mm f/4.0-6.3 EX APO RF HSM for Canon

06/11/2005 10:13:37 AM · #13

there dynamically recompressing the images after you upload them.

Canon 12x IS USM (S3 IS built-in Lens) -- 36-432mm (35mm EQ)

06/11/2005 10:23:09 AM · #14

Originally posted by gusto:

there dynamically recompressing the images after you upload them.

I don't think so ... I think the only thing which happens is that any EXIF and other info is removed.

If the site were modifying the photos, huge numbers of people would be experiencing these kinds of difficulties, not just the isolated member here and there.

Message edited by author 2005-06-11 10:24:48.

06/11/2005 10:25:44 AM · #15

Originally posted by justine:

Originally posted by Alienyst:
Thanks for the suggestions but they all assume someone is using PhotoShop.

What do you use?

PhotoImpact 10.

06/11/2005 10:27:58 AM · #16

Originally posted by GeneralE:

If the site were modifying the photos, huge numbers of people would be experiencing these kinds of difficulties, not just the isolated member here and there.

If you were sitting here in front of my monitor right now and saw the difference between the image in PI, my browser, and on the DPC site, you may change that opinion. In PI and when it is just opened in the browser (no on DPC) the image looks clear, crisp, very clean. The uploaded image on DPC looks dark, fuzzy, noisey. It seems to me that people have figured out how to overcome this but it requires PhotoShop.

Message edited by author 2005-06-11 10:28:37.

06/11/2005 10:30:34 AM · #17

Originally posted by GeneralE:

Most editing programs will have these same settings though, they just call them by different names. Someplace there will be some settings or preferences having to do with color space or profiles.

Ok, part of the problem solved. If I change my default printer to my professional printer, it automatically enables sRGB colorspace and uses the color management. If I have my HP printer set as default, it ignores it since I don't have a profile set up for that printer.

Message edited by author 2005-06-11 10:36:39.

Canon 12x IS USM (S3 IS built-in Lens) -- 36-432mm (35mm EQ)

06/11/2005 10:36:15 AM · #18

Originally posted by Alienyst:

I have looked and there is nothing to set colorspace to sRGB. There is color management and I do have a profile for my monitor and printer that I created using a calibrator - a Spyder. But it doesn't change the fact that after the image is uploaded it looks like crap.

Can you email me an entry-sized photo in TIFF format? I'll save it as JPEG out of Photoshop and post it, and we can see if the same problem occurs. I should be here for the next half-hour or more.

Canon EF 24-105mm f/4.0L IS

06/11/2005 10:39:50 AM · #19

Originally posted by GeneralE:

Can you email me an entry-sized photo in TIFF format? I'll save it as JPEG out of Photoshop and post it, and we can see if the same problem occurs. I should be here for the next half-hour or more.

See above post. I would love to send you a tiff but I have a problem with those too. I just took a bunch of pics this morning in raw, used the EOS viewer to export as a tiff to PI and it was black even though in the EOS viewer it is a beautiful photo. Not sure why that happens. I tried all the shots I took today and the same thing. So no tiffs for me.

frychikn

Olympus C-5050Z

06/11/2005 10:41:56 AM · #20

I stopped submitting images (admittedly I had not submitted very many in the first place) last fall. I had switched from smart media to Olympus-XD cards in my camera. The XD cards seem to take a higher-quality picture, but they use more bytes in doing so. Submitting my XD pictures at 600 x 450 would give a good quality picture but over the 150K limit. Shrinking the picture a little more to get it within the limit would make it look like crap so I stopped attempting to submit (I don't use Photoshop). Since I couldn't submit any pictures I let my paid membership expire in April. Now I can't submit pictures, I can only observe and 'freeload'.

Artifacts

Canon EOS-5D Mark II

06/11/2005 10:47:44 AM · #21

Originally posted by Alienyst:

Yup... color space not sRGB... that will do it! :)

I think if you look you should be able to find a way to assign the color space setting of your image without having to do something funky like changing your printer.

The important thing to remember is that you normally post-process your images for the printer or print service and drivers you are using and saving it in that color space. Then you convert that to sRGB when saving specifically for the web. That way what you get for the web closely matches what gets printed.

Message edited by author 2005-06-11 10:49:44.

EddyG

Canon EOS-1D Mark II

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

06/11/2005 10:48:08 AM · #22

Originally posted by gusto:

there dynamically recompressing the images after you upload them.

Definitely not. The image data is not changed at all. After the file is accepted, it is processed on the server side -- any extraneous non-image markers in the JPEG (such as Adobe XMP data, EXIF data and color profiles that might be embedded) are removed via the 'jpegtran' utility (see the '-copy none' option) to maximize browser compatibility. During this time, the image data is also losslessly transcoded, so it is conceivable that the JPEG file could actually get slightly bigger (go over the 150KB boundary). But the file size is checked before the jpegtran step, so if it does get bigger, your image is still accepted.

However, there is no pixel manipulation done to your uploaded JPEG. If your images are "dark, fuzzy and noisy" after uploading, it is not the result of anything DPC is doing. (Trust me.) You need to look elsewhere in your workflow, especially with regard to your color space. Your image needs to be converted (not assigned) to to the sRGB color space if that isn't the default, since that is the only color space that browsers like IE will display. I explain this in more detail in my tutorial on preparing images for DPC. Just because it is written for Photoshop doesn't mean that the concepts don't need to be applied in other editing applications...

Message edited by author 2005-06-11 10:57:39.

justine

Canon EOS-50D

Canon EF 28-135mm f/3.5-5.6 IS USM

06/11/2005 10:48:50 AM · #23

IrfanView //www.irfanview.com/
Free and does RAW.
If you don't have PSHOP it's the next best.
Also see if you can find a copy of the old Photoshop LE they came free with many printers and you may find someone that has an extra.

Message edited by author 2005-06-11 10:49:57.