Whats causing PIXELATION of image during POST?

<p>I look at tons of pictures & I see how sharp they are & its driving me crazy! Everytime I get finished with a picture & post it it has a slight pixelation to it. On FLICKER I dont see anyimages like this. Here's how I shoot & what I do during post....maybe something along the line is having a huge effect?<br>

.<br />1. Camera is usually set to shoot large fine (sometime I will shoot RAW but I rarely do)....I shoot large fine so its the best quality before RAW although I do wonder if someone could break down the difference between Large/Med/Small Stairstep & fine...besides the boviouse that Large is a bigger file the Med....<br />.<br>

2. When I get home I will open in Photoshop. I don't do a ton to my pics but I do usually adjust the LEVELS in every pic....slide the highlights arrow to the left slightly & the shadows to the right to add that depth & contrast. Some pics I will make Black & White....maybe Liquify any Wompy looking body parts & Clone or Heal pimples & what not on the face. I will also sometime add my logo & add Unsharp mask or Smart Sharpen...but this isnt on all pics & i see the pixelation on pics where I didnt do this.<br />.<br>

3. I will save an Edited version of the pic, full size...then I will resize in Photoshop by 35-40 percent usually just under half so its easier to upload to my website & other places....and ill save this file as Editedweb.<br />So most of the time Im editing JPegs (usually Fine/Large) I can see this being the problem but I dont imagine every crisp picture I see was shot in RAW...so I have doubt there also. Maybe when Im resizing the image? I just started clicking Bi-Cubic Sharper...it helps but doesnt seem to totally correct the issue. Am I overediting my pics? I dont think so becuase I see peoples pics have clearly been Dodged & Burned all over the place & they are still sharp......This is definetly one of my biggest setbacks in my photography right now so any help would be apreciated! Here's a link to my blog where you can see a lot of the images Ive taken & example of how they are pixelated...especially the one of the Wedding couple in front of the building looking back.......I did do a lot of post to that (Desaturated & pulled out yellow tones...dodged/burned...skin cleanup etc)<br />.<br>

<a href="http://ashleydellingerphotography.blogspot.com/">http://ashleydellingerphotography.blogspot.com/</a><br>

. <br>

Thank you so much for your help : )</p>

Have you tried looking at those posted images on a different computer, or using a different web browser? I don't see

any pixelation or compression artifacts in the image you mention.

<p>Its not huge but its there. I have veiwed on different browsers....it most noticable on the image of the couple looking back (the sdesaturated pic) & the pic of the bridge shot from behind & capturing her reflection.....Its just a slight distortion but its there. Its especially visable if you enlarge your screen....Zoom your computer screen (bottomn right hand corner of the screen) to 150 or 200%......I guess its not as visiable in the show & detail pics.....so maybe thats answers my question....I didnt really edit those pics as much as I did the last two & they look sharper. So maybe my question is "If you are going to do a lot of post to an image....do you have to edit in RAW to avoid degrading the pic quality of a JPEG? And does resizng your pic have a huge affect on pic quality too? (when it compresses the image does it cause a huge qaulity loss?)</p>

<p>I looked at your port (great images!) I see the same thing in yours if you look at Angular Features....its super crisp & sharp...no wierd "whatever you want to name it!" in the pic but then your pic "Rodeo Rescue" around their heads and the details of the pics you see this slight "pixelation" or "distortion".....Im guessing it must be cause by post becuase you probably lightened the pic a little(?) on Rodeo rescue but the Angular features shot in broad daylight probably didnt (?)......I dont know....I just know that I see Brittany Kluse & Other photographer sights & the images are sharp as a tack & if you view my site my images all have this strange defect.</p>

<p>In the case of the two example images you mention, there are some fundamental differences in the exposures. The cowboy, in bright sunlight, was able to be shot at a low ISO, which helps to maintain contrast and saturation and low noise - and the lens was stopped down, and we have a nice high shutter speed. All of those things lend themselves to clarity. The noctural rodeo rescue shot, on the other hand, was shot at a high ISO (so, lower contrast and more noise), a wide aperture (so, the lens was not at its sweet spot), and a low shutter speed (so the subjects' movement isn't frozen, and any camera movement is very evident). To make matters worse, there's a fair amount of glare of bright lights hitting the lens from just out of the frame, and you're seeing a lot of backlit dust in the air. There are more sharpening artifacts in the night-time shot than there are in the broad daylight shot.<br /><br />I think it will help if you work on refining your vocabulary for each of the things that detract from the quality of a final image (not counting composition, lighting, etc). For example, here's an image, and then a pixelated version of the same. See how adjoining pixels are chunked into having the same value, so that you're seeing large blocks of the same color/tone? That's pixelation.</p><div></div>

<p>And here's a case where I've deliberately WAY over teased-up the shadows on a horse shot. The noise in the shadows becomes very evident.</p><div></div>

<p>And, here's an example of compression artifacts. If you try to reduce the file size (not the dimensions, in pixels, but the size of the file in bytes) too much as you render the final JPG, you'll get banding, blocking, and loss of detail. It looks like pixelation, but it varies based on what's going on in a particular part of the image. This is a <em>highly</em> compressed version, but you get the idea.</p><div></div>

<p>It's worth mentioning that some people will <em>see</em> what looks like compression artifacts even when they're not there - often because of how their display is set up, or limits in their video hardware, etc. That's why I recommended visiting the same images from multiple computers/displays.</p>

<p>It's also a good idea to make sure your computer is set to view your screen at it's optimal size. If your screen's optimum view is 1280 X 1024 , don't view it at 1024 X 768.</p>

<p> </p>

<p>Great information & you've helped me identify the picture bandit as "Jpeg Compression Artifacts"!!!!!! So thats happeing when im downsizing then? My passion is to shoot high fashion...but I typically will do a lot of post....so I wasnt sure if it was doing post work or the resizing that was causing the quality loss. This image that Ive attatched is a good example of what I want to acheive quality wise. Im aware the lens & light have a lot to say about the final quality but the compression factor is my main concern. Maybe they are using Hasselblads & its my camera? A Canon 7D is good but a lower end camera...runs about $1600. What do I do to resize the image without causing the artifacts?

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<p>A few things:<br /><br />1) Get used to working with RAW files. Don't turn them into JPGs until the <em>very last moment</em>. There is a lot more latitude, there. When you're telling part of the image to change its tone curve, it helps to not already have some of those pixel values maxed out or lost down in noise-ville, in the shadows. <br /><br />2) When you DO create a JPG, work with different compression ("quality") values as you save the file. Images with different complexity or tone gradients will tolerate different amounts of compression, so you have to develop a sense for how to approach that. This has nothing to do with which camera you're using.<br /><br />3) Be careful not to post other people's images, so that you're not reproducing them without having rights to them. If you want to show an image as an example, and it's someone else's, just link to it.</p>

<p>Another thing you might want to keep in mind is that EVERY single time you open a JPEG file and then save it again (even if you've done NOTHING to it), you effectively reduce the quality, even if it's only by a tiny bit, even if you've set your software to save at the maximum quality. You lose something each and every time... that is why we always recommend you shoot in RAW - that way you always visit the original image in a non-destructive way AND you have a greater latitude for manipulation...</p>

<p>Ashley, are you sure you're a beginner photographer with those professional high end looking images on your blog?</p>

<p>Oh, wait minute. Of course you're a beginner, you've shown you don't have the business experience to know not to post another photographer's image without giving them credit.</p>

<p>I don't see any artifacts in any of your images. In fact your images look better than the one you're wanting to emulate.</p>

<p>Tim, et al, am I crazy, or did Ashley just modify her Photo.net "Photographer's Biography" page? </p>

<p>When this thread first opened, I casually looked at her bio, but didn't pay much attention to it. However, when I just looked again, it seems to have been stripped of most of the content.</p>

<p>Tom M</p>

<p>mmh, Tom, no I wouldn't say you're crazy. Didn't dawn on me to go to Ashley's PN profile. I was too busy looking at her beautiful images on her blog she linked to.</p>

<p>What do you make of your observation? I haven't a clue to what it implies.</p>

<p>I don't pay too much attention to when information leaves or stays on the web, just the quality of the information and whether it teaches something new.</p>

<p>But I do appreciate your diligence, Tom.</p>

<p>Hi Tim - No, I don't know what it means ... in fact, I originally paid so little attention to it, I truly can't say for sure if it really changed (i.e., removed the actual bio) or not. </p>

<p>Tom M</p>

<p>Im so confused. I cant tell whether Tom Mann & Tom Lookingbill are the same person pretending to be two people or what and whether Im offended and wierded about the interest in my profile or flatterred that you say I have nice work.</p>

<p>I dont recall changing my profile & so if I did it was done mindelessly with no intention behind it & thus certainly not worth so much thought. I certainly am not hiding anything since my blog and website & facebook are all very 'findable'........feeling confused.</p>

<p>Anyways....no I didnt ever say I was professional/beginner etc...I am me & I dont try to label myself. No one is professional as it entails you know a whole lot when really none of us do....we should always be learning and moving forward in our techniques & ideas. I didnt credit the other photographer becuase your right....Im not a business woman....Im a picture taker. Will make note of that in the future....didnt really think to caption the photog although its clearly a good idea.</p>

<p>Anyways....I do see some compression in my images...you see it a lot around people logos and wherever they edited the picture quite a bit. Its like makeup....it makes you look better but no one should know its there and the compression artifacts are a little trail of breadcrumbs to the trained eye....I want what I edit in the pic to be a mystery & not have artifacts pointing arrows to it. This thread has ultimatly led me to an additional question (and thank you matt & mario for all your insight)</p>

<p>"If I edit a picture then save it (at highest quality) as "Edited", then I go back and make additional changes to the image without closing it...maybe llike making it BW so I have a BW copy too and so I save that same JPEG again but as a new name "EditedBlackwhite".....am I still losing quality? ..................Do you lose quality if you keep resaving no matter what or only if you keep saving that JPEG as the same file name? (ir hitting save instead of save as and changing it to a new saved file each time"</p>

<p>Thank you again!</p>

<p>Hi Ashley - I certainly didn't mean to weird you out. Let me try to explain. </p>

<p>You may not have claimed to be a beginner, but you posted your question in the "Beginner's questions" forum, yet every image that I saw on your blog and website were of such a high quality that no beginner could have possibly have taken them. Furthermore, it became clear from your comments that you know your way around at least some parts of Photoshop quite well. </p>

<p>In contrast, even the title of your thread suggests you are a novice photographer because you clearly didn't know the definition of the word, "pixelation", yet your blog contains images that show absolutely no pixelation, show excellent sharpness, etc. No one could possibly generate such high quality images unless they already know a lot about JPG compression, the resolution (in pixels) needed to avoid pixelation when displayed at screen dimensions, etc. So, the bottom line is that there seems to be a strange disconnect between what you say and the images you have on your blog and website. This is the issue that I think Tim was suggesting. </p>

<p>Every month or so, it seems that someone comes through photo.net either (a) claiming to be an expert photographer and we come to find out that they are posting images on their blogs/websites that they didn't take, or, less commonly, (b) claim to be a beginner and it rapidly becomes obvious that they are quite accomplished. The motivation for the 1st group is clear. I've never been able to figure out the motivation of the 2nd type of person. Once Tim raised the above issue, I wanted to see what he was talking about and clicked on the links (that you provided) to your blog and website.</p>

<p>It occurred to me is that you might be a good photographer and know a bit about PS, but not know the incredibly basic principles and terminology such as Matt covered in his posts, so you simply employ someone (e.g., a photo-savy webmaster) to do the resizing, output sharpening, color space conversions and other work required to post the high quality images that we see on your blog and website.</p>

<p>If you understand why some of us would see this as paradox, and feel like chatting, perhaps you can provide some insight into this discrepancy. </p>

<p>Sincerely,</p>

<p>Tom M</p>

<p>PS - WRT to Tim and I being the same person, I can assure you we are not. He's somewhere out west (...I forget where...), and I'm in the Washington, DC area. I've never met Tim, but we cross paths on this forum fairly often. If you do a search, you'll see that both of us have posted self-portraits, and don't look anything like each other. OTOH, we often agree on technical matters.</p>

 

<p>Tom, stop talking to yourself. Remember, I'm you. Or were you talking to me?</p>

<p>BTW, what does WRT stand for?</p>

<p>But yeah, ashley, what's up with you having drop dead gorgeous images and not know anything about jpeg compression artifacts which at least three people with calibrated and profiled displays on this thread can't see on your blog? Do you know how many times I've had folks do the same thing throughout my years helping folks online on several different digital imaging forums I've frequented? That's old school now.</p>

<p>Besides, Tom's the suspicious one. ;)</p>

<p>About your (b), Tom. Someone who claims to be a beginner and obviously by the look of their work is not, but directs forum contributors to visit their blog off site pretty much addresses the motivation behind it. They want folks to visit their blog!</p>

<p>This reminds me of a discussion on marketing caveats I had in my local park with someone who thought they could advertise to the world for free on the web until I pointed out the fact that they still had to pay for advertising to get folks to visit because no one knows or has heard of their name. They countered with the misconception that google rankings and indexing will put them at the top of the search listing where I had to counter with the fact that their future clients wouldn't know the name to use to do the search that would lead them to their blog or site and embedding tags won't put them at the top of the listing either. However, Photo.net has a lot of traffic and very good google rankings and any discussion about photography on their site puts those in the discussion a lot closer to the top of the listing, but even that's not guaranteed. </p>

<p>All of us here give freely of our time and expertise and we like helping people. I've been doing it since around 2002. It's now a hobby for me.</p>

<p>You've started a thread on a problem that doesn't look like a problem from some one who should obviously know better and I'm dumbfounded as to how you don't know about jpeg compression. And we could go even further by adding that you must not know how to do a google search on such a basic digital imaging question to get your answer.</p>

<p>This is a forum for Beginner Photographers.</p>

<p>Come up with a more challenging question that a professional such as you would ask, but you'll get better answers from other professionals in the Digital Darkroom forum. Welcome to Photo.net.</p>

<p>BTW how did you create such beautiful images? Whoops! I'm not a beginner. I should know how to do that. Never mind. :)</p>

<p>Thank you for the compliments but I have to disagree. I do like my work but I guess I will have to figure this out on my own. Im not crazy or looking for traffic to my blog (it doesnt get any traffic and I dont mind that.) I put that link so there would be several pics to show the quality I put out versus me only uploading one pic. I see edited images by other professional photogs & they are crystal clear. I tried to open some of my pics and circle specific spots where Im bothered by the lack of clarity but theres no one spot to choose...its really an overall quality loss. I see the huge images sharp as a tack & they dont look processed...they look straight out of the camera.....my images look processed & its not 'obviose spots where ive edited' but the overall quality of the pic shows its been edited & that bothers me. I posted in the beginner forum becuase I figured it WAS a basic question & that seemed like the best spot to post...maybe I will repost in Darkroom but I thought that was only for film? Anyways...thanks to all your help at any rate.</p>

<p>Whenever I clicked on your blog link, it made my internet connection freeze, so I gave up. Any way you can post the example image in this thread?</p>

<blockquote>

<p>I put that link so there would be several pics to show the quality I put out versus me only uploading one pic.</p>

</blockquote>

<p>If you'ld post here we could also rule out if your image hosting site or who ever is providing you the bandwidth for your blog isn't adding additional jpeg compression which is common among different image hosting sites. We may not see anything since we didn't see anything on your blog, but it will at least rule out for YOU whether it's your site's fault for what you see.</p>

<p>But just to point out, even if you do find out the cause it doesn't look like you'll be able to do anything about it anyway. It's clear you see something we don't and maybe it's because you're just to close to your images from an artistic and emotional stand point.</p>

<p>Also, hope you're viewing on a calibrated and profiled display in a color managed browser.</p>

<p>I just saw my gallery images on a high end HP system at Best Buy attached to a brand new uncalibrated HP brand HD LED display and they look HORRIBLE. They're all overly bright, skin tones have a heavily brownish yellow (yellow ochre) cast with overly crispy/noisy edges viewed in MS Explorer which is a non color managed browser. But it wouldn't have made a difference anyway if it the browser was color managed because I'm convinced no profile, not even a canned one, in the world could fix what I saw.</p>

<p>This thread:</p>

<p>http://www.photo.net/casual-conversations-forum/00Y85V</p>

<p>...may sheds some light on the line of questioning this thread took. </p>

<p>Apparently Photo.net has become a nice site to sidle up to, but that's what pays their bills.</p>

<p>Tim: WRT = With Respect To, e.g., <em>"...WRT to Tim and I being the same person, I ..."</em></p>

<p>Ashley / Tim: I think I figured out why it looked to me like some of her info disappeared. It probably was a page load problem with her blog, like Nadine described. In any case, it's all back ... at least for right now.</p>

<p>Ashley: I think I may know the source of the"pixelation" problem you are encountering. The hint is in one of your early posts. You said: <em>"... Its especially visable if you enlarge your screen....Zoom your computer screen (bottomn right hand corner of the screen) to 150 or 200% ..."</em>.</p>

<p>Say, you are looking at a 300x300 pixel image on a web site. You then "zoom your screen" to 2x. This forces the browser to try to generate a 600x600 pixel image from the lower rez version. Essentially, you are asking your browser to guess at three quarters of the pixels at the new, higher resolution. There are various algorithms to guess these numbers, but the bottom line is that it is still a guess and the zoomed image is guaranteed to look pixelated. My guess is that this is what your are seeing.</p>

<p>Furthermore, my guess is that on those websites which you feel look good at any zoom level, the photographer or web designer either has uploaded various sizes of each image, and you always get the closest fit, OR, they have simply uploaded a high resolution version of the image, so that the browser never has to make up data when a viewer asks to zoom in. Essentially, they only crop the image to the dimensions requested. If a view of the entire high resolution image is needed to fit in a smaller number of pixels, very good algorithms are available (e.g., "Lanczos") to do this without pixelation or stair-stepping.</p>

<p>Does this sound like what you are seeing?</p>

<p>Tom M</p>