Layer Masks

in this lesson I'm going to show you one of gimp's most powerful tools layer masks a layer mask will let you dynamically and effectively choose what portion of a layer is visible and what portion of a layer is not visible this is done by using an image that runs parallel to a specific layer and you'll see whatever what I mean in the video tutorial here and if you like any of the images that you see here check out the description area below and I will have a link to all of the tutorials to these images alright before I actually show you layer masks I'm going to show you a little bit of what the eraser tool would do in this case and hopefully this will clearly explain the benefits of using a layer mask instead of using an eraser so if I start to erase on this blue layer you'll see that it pretty much just makes that portion transparent it erases that blue away so if I hide my blue layer you'll clearly see that the green layer is still underneath and it is visible because I'm erasing the portions of the blue layer now the problem with this is if I let's say I wanted to change the color of that blue to red now you could go into the colors hue/saturation and change it like that but what if I wanted to do it with a bucket tool what if I knew the exact color that I needed well it would be a little bit of a challenge to effectively get that done because if I click on my bucket tool and I fill it's not going to fill what I want it's just gonna try to either fill in the whole thing or it'll fill the similar colors and you can see it's just not giving us the result we want look at that blue image it just doesn't work out now if you take a layer mask and do this it'll create a completely different result so what I'm going to do now is I'm going to hide this layer for now and create a new layer and fill it up with that same color blue just to show you what happens all right so now what we're going to do is we're going to right click on this blue layer and we're going to add a layer mask now the layer mask will ask me how I want to initialize the layer there's plenty of different ways to do this but for now we're just gonna leave it on white fool opacity and click Add now you can now you'll see that we have two images here we have blue image which is our layer and the white image here which is our layer mask now the layer mask like I said earlier is nothing more than an image that runs parallel to a specific layer in this case it's going to be in this layer right here now if I right click on this layer and I click show layer mask what you're gonna see is you're gonna get a clear look at what our layer mask looks like right now it's nothing more than a white image now if I click on my paintbrush tool and I start painting black on this it's just gonna look like a black on white image now if I also go ahead and let's paint let's paint halfway through it let's paint gray let's add some gray pixels in there too and then I right click on this layer mask and I uncheck the show layer mask option what you're gonna see is all of these black pixels are going to turn green and all of these gray pixels are gonna turn some kind of clean and blue mix and the white is gonna stay blue okay and just like I said that's what happened now what's actually going on here is the black represents transparency the white represents opacity and the gray represents a mix of the two essentially this is emulating the eraser tool and it's doing a lot of the same things as the eraser tool the only difference is our original image is untouched if I right click on this layer mask and I uncheck or I check the disabled layer mask what you'll see is our layer mat our layer itself is still blue it's still the same it's still unchanged and we can edit it however we want but no matter what we do to that layer whenever this layer mask is active all of those transparencies and things like that are going to still be there okay now that you've seen the layer masks and a little bit on how they work I'm going to show you why it's so much easier to work with these instead of the eraser tool okay so first off let's go ahead and try to add a gradient to this blue layer okay with the layer mask still active and everything turned on and normal let's try adding this fire incandescent gradient and see what happens how about that it creates that gradient and it still keeps all of that transparency data like I had said earlier so if I hide the screen layer you'll see that those checkerboard parts are transparent and that's being directly affected by my layer mask if I were to click on my paintbrush tool click on my layer mask and then start brushing the color black you'll see it's just going to add more transparency to my image and alternatively if I switch over to the color white and I start coloring white it's going to remove that transparency now let's try to do the same thing with the eraser tool version of this let's click on our gradient and try to create that gradient and see what it did it just wiped out all of that transparency data and it's all gone whereas on here I can make gradients all day it doesn't matter it'll always stay there now the cool thing about layer masks is you can also add gradients and do all kinds of stuff to these images so for example let's add another new layer and this time we're going to hide our layer mask again and we're going to fill this layer with that color blue and now I'm going to right click and I'm going to add a layer mask I'm gonna set it to white full opacity again and click Add now I'm gonna reset my colors to black on white and click on my blend tool set my gradient to foreground background and make sure I'm clicking on my layer mask so that anything in it not might layer and I'm just going to create this gradient and you'll see that it created a blue to look in gradient from these two layers because it added that transparency information this is incredibly powerful because now instead of having to create a custom gradient or anything like that I can simply just change the color this color blue and whenever I change that color blue it's just going to change to whatever color I want it to be so I don't like that red on green gradient I can make it an orange on green gradient it's so much easier than trying to edit and create your own custom gradients a very good example of where layer masks really came in handy for me is going is for the tutorial for my product photography using I'll go ahead and link to the complete tutorial for this image below check it out if you haven't already but I figured I would go ahead and touch base on this and show you a little bit of exactly where layer masks came in so handy here first off let's look at let's look at this part right here so this layer is let's hide all the extra layers okay so this layer here is nothing more than a duplicate of my base this is my base layer and here's the duplicate layer now the thing is the duplicate layer the only part that you can actually see is a very small portion of it because of my layer mask I disabled my layer mask here and now you can see this is the original version of this image so here are the two images that I'm using to combine together I wanted to get the black background of this image but I wanted to get the light foreground objects the box and the labels and things like that from this image so I had to use layer masks to get that done I could have you know tried to brush in the color black and use select tools to you know select stuff and delete stuff and do stuff like that but it just it gets very messy and if you make a mistake it's really hard to fix it whereas with layer masks you're never actually deleting anything you're just adding more information which that information you can always easily remove at a later point so let's go ahead and re-enable that layer mask and let's also just show you the layer mask itself you'll see it's nothing more than uh it's pretty fuzzy I just use the fuzzy brush at different shades of grey black and white and I just brushed in the areas that I want it to be visible and as you can see all of this black area is completely unchanged and it shows the under the layer underneath which is my original version so you can see with the combination of the two I was able to effectively remove all of that extra stuff that I didn't want here's another tutorial that I've already done in the past again I'm going to go ahead and Link this logo tutorial below but I wanted to point out again the value of layer masks and this image if I right click on this layer mask here on this layer which is nothing more than the little Android dudes body if I right-click on that and I click show layer mask what you're gonna see is it's actually this time it's a completely black on completely white layer mask so the image itself should be completely that bright colored green but he's not because instead of making that odd color of gray I just went ahead and stuck with white and I just adjusted the opacity here because that gives me a nice dynamic and easy way to modify how visible or non visible that portion of the image is now about back to the android logo portion another thing to note is you'll notice that he is the layer mask his shape is a layer mask not the image itself the image itself is nothing more than a green just a complete rectangular greening object now if I right-click on that and I understand what the layer mask you'll see that my layer mask is defining my edge and since he's a single colored object this is really easy to do and actually if you look and watch that tutorial you'll see a lot of how this layer mask made this result looks so much nicer because before there was a nasty white edge along it and stuff like that just check out that tutorial and you'll really see some of the power behind layer masks ok so now that you have seen a couple more examples of where layer masks really come in handy let's go ahead and take a quick second to see what happens whenever you try initializing that layer mask in a different way let's right click on this background layer and let's add a new layer or actually let's let's just duplicate the layer and we're gonna go ahead and hide our background for now and I'm gonna right click on this layer and I'm going to click add layer mask now there's white full opacity which you've already seen it just essentially makes your entire layer mask white black full transparency does the opposite it will make your entire layer black or in other words it's going to make everything on that layer disappear until you start brushing in white layers alpha channel that I works with I'll just click and show you in this case there's no alpha channel on this image so it just made the whole thing transparent it's not really something I use very often usually if I do anything I'll use white full upper transparency black full transparency sometimes I'll use selection or grayscale copy of layer and what selection will do is if you click on your selection tool and let's say you have this you know really nice complicated selection or you know you actually took a path the paths tool and you traced out a specific object and you want to isolate that object and gift well you know with the paths tool you can trace your path and then in your path you can click path to selection and that'll turn your path into a selection and with that you can then right click and click Add layer mask and you can set it to selection and what's going to happen is everything is going to disappear except for your selection so now if you click on your paintbrush tool you're able to still change your layer mask if you look at your layer mask it it's just a white it just took your selection and made it white and fill the rest with black you know if you brush over here white it's going to make that portion of the image visible again or alternatively as always if you paint black it's gonna make it all go away so let's go ahead and duplicate that layer we're gonna delete its layer masks that we have so we're able to put a new one in let's make it visible right-click add another layer mask and this time we're going to do grayscale copy of layer um this is a pretty cool tool it's often overlooked and the capabilities of it are through the roof really usually I use this to effectively isolate a specific object from a background specifically if you look at the beginning of my Samba tutorial I'll link to that too there's a video at the beginning of that that shows you how the grayscale copy of layer comes into play so as you can see here what it did was if I right-click and I show my layer mask again all it did was it took my image made it black and white and popped it on my layer mask so if you have an image that's black on white or you want to highlight you know only the light pixels and you want to make the black pixels disappear on your image you can do that so now if I were to let's let's unshown my layer mask and let's go ahead and delete everything on my actual layer and just fill it with the color black and as you can see it creates a pretty weird effect but I'm gonna show you a little bit more in a second all right so now I've got this odd-looking black type effect on this image and the rest of its just transparent now what's going on here is if I show my layer mask again you're gonna see that there's a bunch of black pixels on this so the majority of this image is invisible because a majority of this image is dark the only parts are clearly visible are parts of the waterfall where it's white and the sky where it's overexposed and white so if I right-click on this and I uncheck my shoulder man again you're gonna see the very clear black pixels there because my layers black if I were to fill this with a different color like blue oops I colored my layer mask that's why you got to make sure that you always click on your layer before head and you'll see all the blue pixels are representative of any color that isn't completely black in the image now here's a cool thing though if I right-click and I show my layer mask again you can edit this with all of those exposure tools that you've learned about in the past so if you clicked colors invert it's gonna make this look pretty wicked but the thing is if I right-click on this and I uncheck my show layer mask it's gonna make most of my image in color now because I effectively inverted the image and I'm inverting what's visible and what's not visible you can also click colors curves you know you can darken this you can lighten it you do whatever you want to create that result that you want the use of this like I said it's very expansive for the most part I use this to remove specific parts of an image that are really overexposed or something like that I also use this a lot on as I said before removing a person including hair this is really nice to get hair out of an image because you can do the colors curves tool and stuff like that and it will make the hair darker and the background lighter which would eventually effectively pull that information out again I would show you that but I've already shown that before on my zombie tutorial so I just went ahead and linked that below this lesson could go on forever I could literally sit here and explain to you all of the different wonderful ways that a layer mask can effectively isolate a portion of an image for you but for the purpose of this lesson I wanted to simply explain to you how they work that way whenever you see them again in my later tutorials you have an understanding on what's going on why I did that and how it's doing it I hope this helps and if you have any questions please leave comments in the comment section below and also take a minute to subscribe to my newsletter signing up is going to give you five exclusive lessons a free ebook by me and I will also email you periodically asking to see how you're doing with what your problems are and it'll give you a direct communication between you and me to talk about your projects we camp how things are going what you're struggling with and what not

Channel: GimpedTutorials

Views: 40,752

Keywords: Layer, Masks, gimp, how to use gimp, gimp for beginners, gimp how-to, how-to

Id: rRBXzVzwEoM

Length: 18min 11sec (1091 seconds)

Published: Sun Jan 22 2012