Join Deke McClelland for an in-depth discussion in this video Testing the quality of edges, part of Photoshop CS4 One-on-One: Mastery.
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In this exercise, we are going to test the quality of our mask, and we are going to do that by transporting this masked hadrosaur right here into a different background. And that's when you really get a sense of whether you've done a good job or not, and we have, but not perfect. Anyway I'm working with two different images. I have opened Duckbill in tent.tif, and The planets.psd, and I'm going to press the Q key to exit the Quick Mask Mode and convert my mask into a selection outline. If you are just joining me a very similar mask, not exactly the same because I made some different decisions this time around, by Ctrl-clicking or Command-clicking on the channel called maskosaur here inside the Channels palette.
Then what I want you to do, assuming you are working with tabbed windows like I am. Go ahead and press and hold the Ctrl Key or the Command Key on a Mac, and that get you the Move tool temporarily of course, drag that dinosaur up there, and notice I'm leaving a strangely colored hole in the background. That's thanks to the fact that I have been monkeying around with the Color Range command, which ends up changing the foreground and background colors. Then I'm going to drag this guy up to The Planets.psd to that Title tab right there, wait for Photoshop to switch images. Drag your cursor back into the image window. Press the Shift key and drop. But if you are not working with tabbed image windows, you can see two windows at the same time, then you can just do a standard Control+Drag+Shift+ Drop, Command+Drag+Shift+Drop on the Mac, without having a resort to these tabs here.
Anyway, by virtue of the fact, I press the Shift key when I drop the scale, went ahead and registered it in the place, inside of the strange composition, where we seeing the earth, from the earth. But the idea is this is the traveling dinosaur planet, it can move through space, and it's visiting earth. We can see earth in the background. Now the only question here, of course it's strange that this hadrosaur is sitting here on dinosaur planet, but the strangest think is he must really be far in the air. But that's okay, I kind of have the notion of standing and it's just very tall. But what's more important than any of that is how does our mask fair? Well let's go ahead and zoom in on it. That's the only way we are going to see.
Here I'm viewing the composition at 200%, and you can see some pretty ragged edges going on, although I have to say the edges are very accurate. And then if you scroll up here to the nostril, it's pretty jagged and not necessarily accurate. We do have a little bit of green that's showing up there, and a little bit of sort of aberrant background jagginess going on. And then, if we scroll all the way over to the right-hand side, this is very bad over here. So the question becomes what you do about it? Well, the couple of different things we could do. One is I'll go over to the Layers palette here. One option notice that we have a new layer, and we have transparency, basically the transparency is now been hardwired into this layer. Bear in mind, we don't have direct access to this so-called transparency mask. But Photoshop uses to track the transparent pixels inside of a layer, as suppose to the opaque pixels.
So we have gone ahead, and just completely shaved away those pixels that are outside the dinosaur. Our problem though is we need to shave very more pixels, so I could add a layer mask and I could paint away some of these edges, if I'm feeling bold, I could just go with the Eraser tool. However I'm here to tell you that there is a better to work. I've shown you the Color Range command and I showed you the Quick Mask mode, and I want you to see those functions, especially Color Range, because you'll be using Color Range a lot in your own compositions, in your own imagery. However I also want to show you a better way to work inside of Photoshop CS4.
We now have this Masks palette right there. And I'll go ahead and twirl it open. Now right now it saying No mask selected, and all the options are dimmed, it is the handy facilitator where masking is concerned. What I really appreciate about it is it forces us to get into some good habits. And so what we are going to do is we are going to backup here. We are going to redefine our selection. We are going to start over from scratch. We are going to do this in a way that affords us more flexibility. So we are going to still end up with the result that we see on screen right now. But we are going to be able to fix this image with a lot more control, as you'll see if you join me in the next exercise.
Recommended prerequisites: Photoshop CS4 One-on-One: Fundamentals and Photoshop CS4 One-on-One: Advanced, both part of the lynda.com Online Training Library®.
Download Deke's customized keyboard layouts and color settings for Photoshop from the Exercise Files tab.
- Defining the essentials of masking
- Resizing images with content-aware scaling
- Adjusting perspective with Vanishing Point
- Applying Smart Filters to create complex effects
- Using the Auto-Align tool to build composite images