lost clarity - DPChallenge Forums

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

03/26/2004 12:51:26 PM · #1

I'm having a bit of a problem that perhaps someone out there can help with...when I resize my photo to comply with the editing rules, I loose clarity in the overall image, any ideas how to compensate for that?

ChrisW123

Canon EOS-1000D Rebel XS

03/26/2004 01:18:01 PM · #2

Dave, when you resize your image for DPC, the final result (usually 640x480) it should look exactly like the original when viewed at 100% as the orginal did at the same size at 25%.

How are you resizing your image? If you Unsharp Mask, be sur to apply that filter after you resize down to 640 x 480. Also when I resize, I do it in increments instead of resizing just once all the way down to 640x480.

cpanaioti

Canon EOS-40D

Canon EF 70-300mm f/4.5-5.6 DO IS USM

03/26/2004 01:20:01 PM · #3

Resizing will always soften the image. It is generally good practice to apply Unsharp Mask after you resize.

goinskiing

Canon EOS-6D

Canon EF 24-70mm f/2.8L USM

03/26/2004 01:29:28 PM · #4

Originally posted by daveit:

How familiar are you with the program you are using? Is this just trying to learn how it works, or has this become a new problem? Generally, resizing an image will decrease some, but nothing that can't be compensated for using un-sharp mask.

If you are using PhotoShop, is it after you save? Because if you are losing quality after you save, it may be because you are compressing the image a bit too much. It has a scale of 1 to 12, 1 being the lowest quality (less in kb) and 12 being the highest (less compressed, more kb). Generally, I can get most shots at 640x640 in the 7,8, and 9 area.

03/26/2004 01:34:34 PM · #5

Originally posted by goinskiing:

Originally posted by daveit:
I'm having a bit of a problem that perhaps someone out there can help with...when I resize my photo to comply with the editing rules, I loose clarity in the overall image, any ideas how to compensate for that?

How familiar are you with the program you are using? Is this just trying to learn how it works, or has this become a new problem? Generally, resizing an image will decrease some, but nothing that can't be compensated for using un-sharp mask.

If you are using PhotoShop, is it after you save? Because if you are losing quality after you save, it may be because you are compressing the image a bit too much. It has a scale of 1 to 12, 1 being the lowest quality (less in kb) and 12 being the highest (less compressed, more kb). Generally, I can get most shots at 640x640 in the 7,8, and 9 area.

It only seems to be showing a poorer quality when I submit it to the challenge and review. It looks fine on PS after I resize it.

Canon EF 28-200mm f/3.5-5.6 USM

03/26/2004 01:40:15 PM · #6

another thought...would it be better to shoot in RAW format and resze from that?

Sammie

Olympus OM-D E-M5

03/26/2004 01:42:51 PM · #7

Perhaps you are compressing too much when you save your image as a .jpeg. Try using as little compression as you can. If you compress too much it will really destroy the quality of the image.

EddyG

Canon EOS-1D Mark II

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

03/26/2004 02:10:00 PM · #8

Dave, you may want to check out this Tutorial on using Photoshop's "Save for Web" feature (assuming you are using Photoshop). When you "Save for Web", you also need to make sure you are saving it as a JPEG and not in some other format (like GIF).

Shooting in raw won't really address this issue.

GeneralE

Canon PowerShot S3 IS

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

03/26/2004 02:52:53 PM · #9

Wasn't there a similar thread a while ago where (at least part of) the answer turned out to be a mismatch of color profiles?

You should try opening the final file from your hard disk using the browser to see if it looks different from when you open the file with the editor.

faidoi

Pentax K10D

Pentax DA 18-55mm f/3.5-5.6 AF

03/26/2004 04:39:58 PM · #10

For people that don't already know: Remember that you can submit and resubmit the entry as many times as you want until the deadline of the challenge. View it and if it doesn't look right change it.

The Server time is on the bottom of the page. Use this to figure out the correct deadline for where you live.

WildflowerJoy

Nikon D90

Nikon AF Zoom-Nikkor 70-200mm f/2.8 VR DG IF-ED

03/26/2004 04:46:51 PM · #11

Is there a special procedure for saving using Paint Shop Pro 7 and keeping the clarity? I have noticed a similar problem with my images. I do submit and resubmit but I can't ever get it as clear on the site as I do on my computer editing program even when I am viewing it at full size. I do the USM after the resizing... in fact I do all changes at 100% then I save it with a new name so the original is not changed. But, the edited version is alway less sharp and seems more grainy after it uploads to the site.

Pentax DA 18-55mm f/3.5-5.6 AF

03/26/2004 10:43:25 PM · #12

That's the problem I was talking about....no matter what I do in editing, it's the same result when I post it.....strange....

faidoi

Pentax K10D

03/26/2004 10:59:17 PM · #13

Photoshop pictures look darker when in photoshop then after it transferred to the site.

whiteroom

Canon EOS-5D Mark II

Canon EF 24-70mm f/2.8L USM

03/26/2004 11:23:50 PM · #14

should one then edit everything in 'quick mask mode'?

Neil

Fujifilm X-T30

Nikon AF-S NIKKOR 24-70mm f/2.8G ED

03/26/2004 11:27:19 PM · #15

Originally posted by daveit:

That's the problem I was talking about....no matter what I do in editing, it's the same result when I post it.....strange....

Have you looked at on the site in a different browser, or from a different computer? Have you looked at the file "locally" in your browser?

EddyG

Canon EOS-1D Mark II

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

03/27/2004 09:08:04 AM · #16

Originally posted by faidoi:

Photoshop pictures look darker when in photoshop then after it transferred to the site.

Only if you don't have your color-space issues properly configured. I don't see any difference between Photoshop and how they look when uploaded to the web somewhere. Try selecting View > Proof Setup > Monitor RGB. (This selects [View > Proof Colors by default, which you can toggle on and off.) Also, make sure when you select Image > Mode > Convert to Profile..., that the "Source Space" says "sRGB IEC61966-2.1". If it doesn't, you need to select "sRGB IEC61966-2.1" as the Destination Space and click "OK" to convert the image to sRGB before "Saving for Web".

I think it would be really nice if Gordon, who is very familiar with color-space workflow issues, could write a Photoshop tutorial on dealing with color-space. (hint, hint =])

Originally posted by goodman:

should one then edit everything in 'quick mask mode'?

That won't help anything.

WildflowerJoy

Nikon D90

Nikon AF Zoom-Nikkor 70-200mm f/2.8 VR DG IF-ED

03/27/2004 09:22:56 AM · #17

Have you looked at on the site in a different browser, or from a different computer? Have you looked at the file "locally" in your browser? [/quote]

I have looked at the image "view for web" in Paint Shop Pro 7 and it looks fine there. The change happens when I load to the site.

03/27/2004 09:22:58 AM · #18

No offense Eddy, but I've already written two tutorials that never got put on the site, so I'm not in any rush to do some more ;)

I might write something up and stick it on my site but probably wont have time for a couple of months, with other things I have to publish.

There are plenty of articles on colour space set up at Digital Dog
that have a lot of the basics well explained.

But basically, you can assume that the web output space should be sRGB. If you import, convert to, or work in any other colour space than that, you'll have problems with colourshifts when you put it on the web. Mainly because most browsers just ignore any tagged colour space when displaying.

Once you've finished any editing you are doing in Photoshop, do:

Image->Convert to Profile

Destination space: sRGB IEC61966-2.1
Conversion Options:
Engine: Adobe (ACE)
{unless you have a real good reason to use another one)
Intent: Relative Colormetric as a first choice, perceptual if you don't like those results
Use Black Point Compensation checked on
Use Dither checked on

You can use the preview option to see the impact of these various options. In many images you will see no difference at all (this is good!)

Then, I use the 'Save for Web' option, with the attach ICC profile unchecked
I use the 'Optimise for Size' drop down and set a target of 147Kb. This will run through various compression settings to find the one that gives you a result as close as possible to 147Kb. I typically use this so that I could re-attache EXIF data to the image later on and still be under a 150Kb file size target.

You should typically see JPEG compression % of about 70% or higher. Anything much lower than that and your image quality is really going to start suffering. There are some images at 640x480 where you can not get a quality result in under 150Kb, but most are okay. Certainly if you cross the 50% threshold there is a step change in the compression algorithm performance, and the results will look terrible. There isn't a whole lot you can do with those images, other than crop differently, or blur them slightly to remove detail.

03/27/2004 09:28:11 AM · #19

Its interesting that Eddy mentions he doesn't see any colourshifts between his Monitor colourspace and sRGB.

I do - Eddy do you happen to have your Monitor colourspace set to sRGB, or to a custom profile ? The 'Monitor RGB' option just picks up the colour space set in your system settings for the Monitor. Not that this is a bad thing or an incorrect setting, but it would explain why you see no change.

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

03/27/2004 09:34:01 AM · #20

The places you might notice changes when you do image->convert to profile (for those who can't see what the fuss is about) is in areas of saturated green, blue, (and probably why this is being mentioned a lot just now) orange.

The rendering intent (perceptual or relative colourmetric) varies how these undisplayable (out of gamut) colours are mapped into the displayable set.

sRGB is a colourspace designed to match typical, cheap monitors, inkjet printers etc and as such can't display all of the same colours as a larger space like adobeRGB. This is particularly true for bright, saturated colours, which cheaper output and display devices have a hard time with - as a result, sRGB is great for the web where you have no idea what people are going to be looking at the picture on, but also you have no idea how their monitor is set up - hence all the 'I don't see orange here' comments I'm getting on my entry :)

EddyG

Canon EOS-1D Mark II

03/27/2004 09:54:42 AM · #21

Originally posted by Gordon:

No offense Eddy, but I've already written two tutorials that never got put on the site, so I'm not in any rush to do some more ;)

Really? Had no idea. Send me a PM and let me know more...

Originally posted by Gordon:

There are plenty of articles on colour space set up at Digital Dog
that have a lot of the basics well explained.

Excellent! Thanks for the link.

Originally posted by Gordon:

Eddy do you happen to have your Monitor colourspace set to sRGB, or to a custom profile ? The 'Monitor RGB' option just picks up the colour space set in your system settings for the Monitor. Not that this is a bad thing or an incorrect setting, but it would explain why you see no change.

My monitor is calibrated, so the "Monitor RGB" option is probably selecting that color profile as you say. Perhaps I need some better examples to "test" for color shifts between "Monitor RGB" and "sRGB"?

When I said I didn't see any difference between Photoshop and my pic after uploading to DPC, I was talking about "drastic" shifts, like you see when you are editing in AdobeRGB in Photoshop, and don't convert to sRGB before "Save for Web". In that case, there is a noticeable shift between Photoshop and the web. So perhaps there are differences between my monitor RGB and sRGB, but I've just never paid enough attention?

Nikon AF-S NIKKOR 24-70mm f/2.8G ED

03/27/2004 10:48:50 AM · #22

Originally posted by EddyG:

When I said I didn't see any difference between Photoshop and my pic after uploading to DPC, I was talking about "drastic" shifts, like you see when you are editing in AdobeRGB in Photoshop, and don't convert to sRGB before "Save for Web". In that case, there is a noticeable shift between Photoshop and the web. So perhaps there are differences between my monitor RGB and sRGB, but I've just never paid enough attention?

The differences I see are mainly an increase in richness of colour for the Monitor RGB vs sRGB, but it is pretty subtle usually.

Neil

Fujifilm X-T30

03/27/2004 10:59:56 AM · #23

Originally posted by WildflowerJoy:

Originally posted by nshapiro:
Have you looked at on the site in a different browser, or from a different computer? Have you looked at the file "locally" in your browser?

I have looked at the image "view for web" in Paint Shop Pro 7 and it looks fine there. The change happens when I load to the site.

Well I don't know if PSP's preview is actually showing it in the browser. But the scientific way of identifying the possible sources of the problem would be to simulate the online environment as closely as possible, except for the DPC part, which is what I've suggested.

Message edited by author 2004-03-27 11:00:30.