Why are my images coming out quality degraded?

Author	Post
nietzsche Deactivated User 5470 Posts 8/03	Posted - Mar 12 2008 : 7:03PM check out my pics here. The other pics on the board don't seem to be doing this. [Link]
nietzsche Deactivated User 5470 Posts 8/03	Posted - Mar 12 2008 : 7:06PM Check out my avatar too. It's lower quality than when I uploaded it. I've tried several times too. [Link]
BigBobxxx Senior Member 2681 Posts 5/04	Posted - Mar 12 2008 : 8:15PM maybe this applies? [Link]
kataboom master blaster ad astra per aspera 995 Posts 6/03	Posted - Mar 12 2008 : 8:39PM im not sure about the pics but i think its a ratio reduction issue. for example if you upload an avatar thats bigger than 10 hex 100 on adt, the site will reduce its size to fit. this html(?) function always make my images look like your avatar. try this neech - take your avatar image & reduce it so the largest side is just 100 pix. upload that & i bet it will look alot better. [Link]
Drew Black broken crankshaft 8011 Posts 9/99	Posted - Mar 12 2008 : 9:36PM I'm not sure why they look that way. What was the source image format? The uploader does do some shrinking on it's own. It increases the JPG compression which lowers the image quality but usually not that visibly. [Link]

kataboom master blaster ad astra per aspera 995 Posts 6/03	Posted - Mar 12 2008 : 9:47PM its not just compression. ive found that the dimensions are the key to the problem. for example, a photo that is 24 hex 130 will compress differently than an image 24 hex 100. i dont know the answer as to why, but ive changed my habits because of it. [Link]
nietzsche Deactivated User 5470 Posts 8/03	Posted - Mar 12 2008 : 11:56PM Drew Black wrote: I'm not sure why they look that way. What was the source image format? The uploader does do some shrinking on it's own. It increases the JPG compression which lowers the image quality but usually not that visibly. Click to expand They're jpg's. And the images are the same size; I don't post and large picture, dimensions-wise or file size-wise. I just notice that the phenomenon only occurs to me. It's no biggie. I won't lose any sleep. I thought i might be doing somethign wrong. [Link]
Drew Black broken crankshaft 8011 Posts 9/99	Posted - Mar 13 2008 : 11:43PM kataboom wrote: its not just compression. ive found that the dimensions are the key to the problem. for example, a photo that is 24 hex 130 will compress differently than an image 24 hex 100. i dont know the answer as to why, but ive changed my habits because of it. Click to expand The resizing for avatars maintains the image's aspect ratio with a maximum dimension greater than 100 pixels in either axis. If either is greater than 100px it picks the larger of the two and the other is scaled back in the same proportion and set to 72dpi for web use. Some jpgs aren't 72 dpi. I'm thinking that the problems Nietzshe is seeing is due to the conversion from X dpi to 72 DPI since the dimensions aren't changing. I think there might be an issue if the original image is less than 72dpi it will still be rescaled "up" to 72 which I haven't specifically tested. [Link]
kataboom master blaster ad astra per aspera 995 Posts 6/03	Posted - Mar 14 2008 : 12:38AM Drew Black wrote: The resizing for avatars maintains the image's aspect ratio with a maximum dimension greater than 100 pixels in either axis. If either is greater than 100px it picks the larger of the two and the other is scaled back in the same proportion and set to 72dpi for web use. Some jpgs aren't 72 dpi. I'm thinking that the problems Nietzshe is seeing is due to the conversion from X dpi to 72 DPI since the dimensions aren't changing. I think there might be an issue if the original image is less than 72dpi it will still be rescaled "up" to 72 which I haven't specifically tested. Click to expand ahhh, i didnt even think of the res. if you ever test it out, post results here. i would like to see what comes of it. [Link]
nietzsche Deactivated User 5470 Posts 8/03	Posted - Mar 14 2008 : 12:53AM Drew Black wrote: kataboom wrote: its not just compression. ive found that the dimensions are the key to the problem. for example, a photo that is 24 hex 130 will compress differently than an image 24 hex 100. i dont know the answer as to why, but ive changed my habits because of it. Click to expand The resizing for avatars maintains the image's aspect ratio with a maximum dimension greater than 100 pixels in either axis. If either is greater than 100px it picks the larger of the two and the other is scaled back in the same proportion and set to 72dpi for web use. Some jpgs aren't 72 dpi. I'm thinking that the problems Nietzshe is seeing is due to the conversion from X dpi to 72 DPI since the dimensions aren't changing. I think there might be an issue if the original image is less than 72dpi it will still be rescaled "up" to 72 which I haven't specifically tested. Click to expand Do you actually program all this graphics stuff, or do you find some code and tweak it. Because if it's the former I am impressed. [Link]
nietzsche Deactivated User 5470 Posts 8/03	Posted - Mar 14 2008 : 12:58AM This is a test, this is only a test. Here is a crop of a screen cap--exactly 100 x 100. Here is the same picture. Edited by - nietzsche on 3/14/2008 12:59:30 AM [Link]
Hardware All-Star Member Your other left 14595 Posts 3/02	Posted - Mar 14 2008 : 2:35AM I grabbed the JPEG and took a look at the file size - 1.64Kb. This is much lower than I get when cropping the original image using IrfanView. [Link]
Drew Black broken crankshaft 8011 Posts 9/99	Posted - Mar 14 2008 : 2:54AM I write most of it. I use a couple of active x object libraries that provide some of the low level functions. Beyond the tasks of accepting the uploaded file, possibly resizing it and storing it, there's a few other things going on too. The uploaded file is virus scanned before being resized. There's an abstraction step that breaks the relationship between the filename you see in the URL and the filename stored on the disk. Every image uploaded to our servers has a number of internal properties associated with each file to keep track of things like approved/deleted/etc. This properties are wrapped up in a custom data cache manager COM object. I wrote another custom COM object that writes the image data out to your browser. It's got a few bells and whistles built in to do the on-the-fly watermarking and image resizing. You can resize an image in the URL by appending a height or width attribute like //img1-ps.adultdvdtalk.com/0850b55a739f4c40a396&w=150 nietzsche wrote: Here is a crop of a screen cap--exactly 100 x 100. Click to expand Just to make sure I'm understanding what you're doing. Are you saving the image to your system by doing a right-click "save image as" or are you doing a screen capture and then grabbing a piece of the screen cap? If you are doing a screen cap that's the problem. When you do a screen cap you lose the original file's color palette and other details. A screen cap is like working with a bitmap file. You'll get crappy results converting from bitmaps to jpegs on photos. [Link]
Patrick S Member 78 Posts 1/03	Posted - Mar 14 2008 : 6:26AM I still don´t understand why you can´t just set a file size limit on avatars instead of compressing them when they´re uploaded to the forum. I guess most people don´t give a crap about this but i´m a bit of a photoshop addict and make lots of fanart stuff and i can hardly use any of my avatars here because they look like crap when they´re uploaded. [Link]
Drew Black broken crankshaft 8011 Posts 9/99	Posted - Mar 14 2008 : 11:48AM Patrick S wrote: I still don´t understand why you can´t just set a file size limit on avatars instead of compressing them when they´re uploaded to the forum. Click to expand And what should that limit be? You might know how to resize and optimize an image to get below the limit but the vast majority of people using this site don't have a clue how to to that. Many (most) don't know how to determine the dimensions or file sizes. Also, if the size of the file is the only criteria (i.e. ignoring the image H x W dimensions) we'd have HTML resized images in the forum that look like crap too. BTW, if you upload an avatar image that's less than 10 hex 100 it will not be compressed. It will be saved as-is. It's only the generic image uploader (not the avatar uploader) that reprocesses all images. We have to reprocess images to be realistic about our bandwidth usage. Our annual hosting costs are close to $30k. If we didn't reprocess images to shrink the amount of data that has to go over the wire we'd be spending much more than that, possibly double. I'm going to look at a few pages just to get some examples of the difference in bandwidth without reprocessed images. [Link]

Drew Black broken crankshaft 8011 Posts 9/99	Posted - Mar 14 2008 : 12:25PM Just as a quick example take a look at the first page of this forum thread. The default settings for someone browsing the site that's not logged in result in a page that is 2,157,133 bytes for images, 84343 bytes for the HTML. (The avatars aren't displayed for users that aren't logged in.) For a regular member with the default 30 posts per page setting and the display of avatars the stats for that page are: 129,638 bytes in HTML, and 2,212,315 bytes for image data. 2.3MB+ for the full page. The addition of avatars alone accounts for an extra 100Kbytes of data for the full page. I browse the forum at 99 posts per page. With this setting I get 346,701 bytes of HTML and 5,523,082 bytes of image data for the first page of the thread. 5.8Mb of data going over the wire to serve just one page to one user. Now think about how incredibly huge these pages would be if we didn't resize the images. The images in these threads are typically very high-resolution photo-quality stuff. They would be 250kbytes to 1MByte each. The page could easily end up being 100MB+. I think it's incredibly reasonable for us to resize these images so our bandwidth requirements aren't utterly ridiculous. It's not like we're running a subscription service here or something along those lines. If we were charging people to use the forum that might be a different story. Here's something else to consider: look at the number of times these threads get viewed. At the moment the sample thread is at 3347 views. It's actually "viewed" many more times than that because our system ignores "views" from search engine spiders and multiple views from the same user within a 15 minute period. Do a little basic math and you can see how the forum can chew up tons of bandwidth. Of course we do some things to alleviate some of the bandwidth load. HTML is sent over the wire in compressed form for browsers that support it. We use the appropriate HTTP cache control directives so user's browsers and upstream web caches can do their thing. These kinds of things help a lot but there's still no better way to control bandwidth usage than to simply not send the data in the first place. [Link]
nietzsche Deactivated User 5470 Posts 8/03	Posted - Mar 14 2008 : 12:59PM Drew Black wrote: nietzsche wrote: Here is a crop of a screen cap--exactly 100 x 100. Click to expand Just to make sure I'm understanding what you're doing. Are you saving the image to your system by doing a right-click "save image as" or are you doing a screen capture and then grabbing a piece of the screen cap? If you are doing a screen cap that's the problem. When you do a screen cap you lose the original file's color palette and other details. A screen cap is like working with a bitmap file. You'll get crappy results converting from bitmaps to jpegs on photos. Click to expand I use gadwin, which allows me to take a screep cap of a portion of the screen, ie I don't have to capture the entire screen first. I guess it's the same thing. That must be the problem. Let me redo. [Link]
Janitor Retired Porno movies, sexy videos, xxx. Adult DVD Talk at your service. 6409 Posts 11/99	Posted - Mar 14 2008 : 1:19PM neech - print screen button on your keyboard puts the whole page on your clipboard - then you can paste anywhere. [Link]
Patrick S Member 78 Posts 1/03	Posted - Mar 14 2008 : 1:31PM Drew, i´m sure all those numbers you mention are correct. The only thing i know is that every other forum i´ve ever been on have a file-size (and resolution) limit and don´t resize the avatars. I´m just gonna leave this alone since this isn´t a fanart board and noone else seems to care about this. [Link]
Drew Black broken crankshaft 8011 Posts 9/99	Posted - Mar 14 2008 : 1:36PM My point in all of that was to demonstrate that there's a lot more to successfully running a high traffic site than simply providing a means for people to have fancy avatars. [Link]
nietzsche Deactivated User 5470 Posts 8/03	Posted - Mar 14 2008 : 5:04PM Steph wrote: neech - print screen button on your keyboard puts the whole page on your clipboard - then you can paste anywhere. Click to expand I know but I practically never need the entire screen. That's why I use Gadwin. I can take as much as I need. [Link]
nietzsche Deactivated User 5470 Posts 8/03	Posted - Mar 14 2008 : 5:14PM Drew Black wrote: We have to reprocess images to be realistic about our bandwidth usage. Our annual hosting costs are close to $30k. If we didn't reprocess images to shrink the amount of data that has to go over the wire we'd be spending much more than that, possibly double. Click to expand OMG I'm going to start clicking more ads. [Link]
Janitor Retired Porno movies, sexy videos, xxx. Adult DVD Talk at your service. 6409 Posts 11/99	Posted - Mar 14 2008 : 5:19PM yeah, buy more porn while you're at it too ;) [Link]
nietzsche Deactivated User 5470 Posts 8/03	Posted - Mar 14 2008 : 6:49PM ok. [Link]