Refined Compression Adjustments
Some images you're going to find that people might not have done you a favor and it might be see if this sounds to be one yes uh that oftentimes I get images that at some point they were scanned and saved and when the person originally saved the image they didn't know the proper settings to use when saving it they ended up using the j peg file format and it got compressed to an extreme amount and when you reopen the picture you can see the jpeg compression artifacts and so there is a method for uh trying to reduce or eliminate jpeg compression artifacts and so first off if you want to see what they look like if you look at this particular image and you look closely at it let me hide one but if you look closely I can you see that the image seems to be broken up into a grid where right here would be one grid unit and the blocks big blocks not individual pixels because I can see that that block that's here is divided up into finer blocks but I can see a definite square blocking us does th...
at make sense those air jpeg compression artifacts and if you say the j peg file in and ask you the quality and you max it out to as high as it goes you probably wouldn't see those but if when you saving his j paige you end up with the quality slider like in the really low settings, you're going to get a bunch of that, and if you end up coming in and doing something like a curves adjustment layer where you click on the dark part of the picture and you might darken it and you click on the bright part of the picture and you might brighten it. Isn't that how we would usually pull out detail in a picture? Well, part of the detail, but this in luminosity mode are those j peg compression artifacts, though that would be a really difficult thing to get rid of manually you doing the retouching, imagine half to retouch every single one of those squares until it doesn't look like squares. Well, well, you have some success trying to get rid of it by coming down here to filter noise there's, a choice called produce noise. Even though this image might not be noisy, we want to use reduce noise because I dismissed it. It has a special feature in here. It's a little check box called removed jpeg artifact. So first we might want to start off with the strength turned to zero and reduce color noise down to zero and don't sharpen the details, meaning get the settings that this thing is actually designed primarily to do, which is reducing noise to be turned off. Because that's not what we're trying to do at the moment, we're instead trying to work with the j peg compression artifacts let's zoom up on the image, then so we can see what it looks like, and I'm actually not seen it as much here, but I'm going to turn on this checkbox removed j peg artifact. Now, do you notice that before, where we used to look like, you can see it more effectively over here on on her image if I turn it off, you saw that kind of grid of blocks if I turn it back on now, you see, the greater blocks has gone has met, and that would be a lot of work if you were going to try to do that yourself, they don't apply it to every image you ever see with artifacts that looked like blocks because it will soften your image a little bit, but it could be amazing if you can figure out exactly how to get rid of those obvious big square blocks. Yes, so so then would that be like the first step you would do if you notice that in a picture before you tried to do anything else? Yes, possibly it would, at least before I did any fine retouching, because the moment I start doing retouching and I start moving those blocks around then this isn't going to be a cz effective in trying to find and eliminate them because it's not just searching for blocks it knows how the j peg file format works and it thinks that those blocks are consistent in size and spacing and so if we started moving around where they're not inconsistent spacing this wouldn't be a cz effective last session maybe it was I don't know when you were working on that photo and you were doing all that fine retouching you this would have been good to do for first yes, it would have a good what I say screen screen like one hundred percent the main thing is you could only see the full detail that's in your picture if the number that showing up is one hundred or higher and sometimes in the newer screens like the new retina screens one hundred isn't sometimes enough it's still so small you have to be like looking really close to see the details so sometimes two hundred percent that type of thing in this case I happen to have five hundred, seven hundred just to make it obvious for you guys because it's not obvious it's not often you sit this far away from the screen, but when you're at a normal viewing distance I could see this when I met probably two hundred percent would be a good, pretty good view for a modern screen another question, but this is about the texture, so the texture on those images is that because of the paper that they were printed on, yeah, the texture you saw in the previous images, yes, oftentimes they're most the time it's the paper was not a perfectly smooth paper. Instead it had texture to it. And then that texture is often exaggerated when it's scanned, because when you scan it image, if you's a flatbed scanner, it's just a light bulb coming very close to the original and scanning across, and you don't have control of what angle that light is coming from and what it's going to do to the reflect since that it's causing on shiny paper so the ones with the really bright highlights that usually means the paper had some shyness to it. So the light reflected off of it quite a bit that's, so that the technique that you said that maybe you want a photograph it with photo rapid instead with your camera instead of a scanner, input a polarizing filter on your lens because with a polarizing filter, you can rotate the filter and can reduce reflections. And so you rotate the filter as you're staring through the viewfinder, until you see the highlights that are in the texture be lessened the most all right, so that's reduce noise.