PS101 Group A - Selection Tools & Masks

Sigma 24-70mm f/2.8 EX Aspherical DF for Nikon

05/12/2007 07:13:58 AM · #1

Spurs,

joynim,

slickchik,

brens29,

JerseyGenie,

bvlindalou,

Chalice,

Di,

Tlemetry,

cpanaioti,

jedusi,

DaveSM,

WORKING WITH SELECTION TOOLS & MASKS
Mentor for this Group & Topic:

levyj413
Topic Author: Art Roflmao

Introduction and Disclaimers
This, and all other lessons put together by me are mostly right out of my head based on my experience. I learn new things about PS everyday, so I encourage everyone to participate in the discussion on the use of tools and methods. You should also feel free to post links to additional resources related to the current topic. Always remember that there is really no "right" way to do anything in Photoshop - find what works best for your style and comfort level.

SELECTION TOOLS
The various selection tools in PS allow you to isolate parts of an image to apply effects or filters to just that area or to copy or cut out an area. There are actually a lot of ways to "select" parts of an image: use a selection tool, CTRL+A (select all), Select Color Range and also variations of some of these.

The primary selection tools I use are the Marquees and the Lasso tools:

- Selects a rectangular area. You can hold SHIFT to constrain the selection to a square. Option settings include a fixed size and fixed aspect ratio - both can be useful for cropping or copying consistent shape and size images.

- Selects a round or elliptical area. You can hold SHIFT to constrain the selection to a circle. Option settings include a fixed size and fixed aspect ratio. This one also has the Anti-Alias setting which softens jagged edges.

- These select a single pixel horizontal or vertical row or column from edge to edge. I have used this for very unique purposes before, but don't find them all that useful.

- Good for rough freehand selection. Hard to control precision even with a tablet and once you let go of the mouse button, the selection is closed/completed for you.

- Good for detailed work and straight edge selections - zoom way in and click from point to point, tracing edges of the part of the image you want to select. Use the spacebar and drag the image to reposition as you go.

- Good for detailed work, but only works well on high contrast edges, but provides a quick way to remove a subject from it's background. Takes some practice to get the tolerance and smoothness settings dialed in to work for a particular image.

- Good for selecting / removing large areas of solid or similar colors. Options allow for contiguous selection or selection of all colors within the tolerance setting. Can be used to work on the contents of a single layer or All Layers. The All Layers option will apply to creating the selection but keep in mind that when you apply filters and effects, they will only be applied to the contents of the selection on the active layer.

- You can ADD to a selection by holding down the SHIFT key and you can SUBTRACT from a selection by holding down the ALT key when using the selection tools. If you accidentally click without pressing a key to add or subtract and lose your selection, just UNDO to get it back. Also remember that the lasso tools have additional options that can be set on the options bar. These include "feather", which will softent the edges of the selection. I rarely use the feather options on a selection tool since I can feather the selection when I am done building it.

For any selection tool that requires fairly high contrasting edges, you can use CTRL+J to duplicate the current layer (assuming everything you want to select from is on this layer), then adjust the contrast, levels, curves for maximum contrast on the edges you want to select. Build your selection on this layer, then switch to the original layer, hide or delete the high contrast duplicate and perform whatever action on your selection now on the original image layer. This works especially well with the magnetic lasso.

Using only the lasso selection tools, remove the subject from its background and place it on a solid white background. Post your completed image thumbs here for discussion and feedback. You can either use this image below, or use one of your own, but try something challenging - not something like an already silhouetted subject. If you use your own, also post the original thumb.

That's all I have time for right now. I will post the subtopic: "Masks" in this same thread in a day or two. Some of this is very basic, but it is a 101 class, so bear with us or check back as the topics are posted if these are too fundamental for you or chime in with your tips & tricks.

Apple iPhone

05/12/2007 08:52:41 AM · #2

i had a heck of a time with its toes.....

05/12/2007 10:16:28 AM · #3

Tamron SP AF 17-50mm f/2.8 Di II LD Aspherical (IF) for Nikon

05/12/2007 03:07:37 PM · #4

Okay, nice job on the first two. You each did well on some things and I have some suggestions for improvement for each of you, too.

I'm still working on my own, actually, so note that this is coming from a sympathetic sufferer, not any kind of expert. :)

Di: you did a nice job making a nice smooth outline. As you'll find, the trick with hair is that it rarely makes such smooth curves. It looks fine against white, but when you put it against something else, it'll likely look like a plush toy, with even-length hairs, as opposed to the somewhat random real hair of a real animal. Not to worry, though - we can use other tools to handle that. The main thing I'd suggest is to try to go back and get rid of the fine dark line right along the top from where the tail meets the back to the top of the ears. Looking at the original, I think those are leftover pixels from the background - his hair is really light, without that outline; look at Colette's version. I also think you did well with his toes. The shadows are real, and would be there whatever he was standing on.

Colette - very clean along the top and back. I don't see anything other than squirrel hair there. As you found with his tail, though, it's very hard to make it look good. Using the various lassos, I've always had to choose between getting all of the hair or getting chunks with odd straight lines. Aside from that, his feet are too angular - try to go back and add in some more of the shadows between his toes. Think about how a real animal looks, not just about a random set of pixels.

Again, good job both of you! The lassos are some of the crudest tools we have for selecting. To me, it's like learning how to do long division so you can appreciate the beauty of a calculator. :)

Message edited by author 2007-05-12 18:27:07.

Tamron SP AF 17-50mm f/2.8 Di II LD Aspherical (IF) for Nikon

05/12/2007 04:07:08 PM · #5

Okay, let me start by saying that I never use the lasso tool because I think there are much nicer ways to make selections. So I'm right with you on the frustrations of trying to get a clean selection using it.

Here are a few tips that can help, though:
1) Along with Art's suggestion of raising the contrast, know how to take a break:
a) Zoom in a lot. I'm working at 300%.
b) After making a selection, shake out your hand, blink a couple of times, and dive back in. Trying to do the entire thing in one go is really hard.

2) The freehand lasso is the hardest to work with because it has to be one continuous selection.

3) The polygonal tool is much nicer because you click and move, but the selection only changes when you actually click. But for smooth curves, you need to do a LOT of clicking. You can close the selection by moving the pointer back to the original spot - you'll know you're in the right spot when the pointer changes back to the same icon as on the tool bar. You can also close the selection by double-clicking wherever you are; PS will draw a straight line from wherever you are back to the starting point. Careful, because if you cross your selection area with that line, you'll cut out part of it.

4) The magnetic lasso can produce smoother curves - play with the width, edge contrast, and frequency settings at the top of the window to see how they interact with the smoothness and accuracy of the lasso tool as it follows the edge. Again, you'll know you've closed the selection when the pointer changes to the same magnetic lasso icon as shown on the tool bar. You can also close the selection by double-clicking wherever you are; PS will draw a straight line from wherever you are back to the starting point. Careful, because if you cross your selection area with that line, you'll cut out part of it.

5) Remember four keyboard shortcuts. They are MUCH faster than using scroll bars, menus, or the navigator panel. These will be so useful in all PS work that you should stop what you're doing and play with them for the next 10 minutes until they become second-nature.
a) ctrl-z (command-z on the Mac): every time you click, if it's not right, undo. Don't wait until you're 12 clicks past what you wanted.

b)space-drag. Even in the middle of a selection, you can hold down the space bar and then click and drag the entire image around. So if you're selecting and you get to one edge of the visible area, this lets you keep going.

c) ctrl-plus or ctrl-minus (I'm guessing command-plus and minus on the Mac): zoom in and out. I constantly zoom in and out, and it can also be useful to zoom out a bit, space-drag to a new spot, then zoom back in to continue selecting.

d) ctrl-d: deselect. Very useful when you accidentally click in the wrong place to start a selection.

Message edited by author 2007-05-12 16:15:23.

05/12/2007 04:33:01 PM · #6

How do you get a solid white background?

05/12/2007 04:36:57 PM · #7

Dont worry figured it out :)

05/12/2007 04:42:32 PM · #8

Here's my first attempt but I'm going to go and try and get a better version

05/12/2007 04:59:24 PM · #9

Ok ran out of time Mothers Day and all will try later :) Thanks Art appreciate your work and effort

05/12/2007 05:02:43 PM · #10

Originally posted by levyj413:

Great post, Jeff! Yes the lasso tool is not the best for removing a subject from it's background, but it is useful for making a quick, rough cutout before taking it into another process - not always necessary, but sometimes useful.

Your tips and points are spot on!

Tamron SP AF 17-50mm f/2.8 Di II LD Aspherical (IF) for Nikon

05/12/2007 06:30:27 PM · #11

Originally posted by Art Roflmao:

Yes the lasso tool is not the best or removing a subject from it's background, but it is useful for making a quick, rough cutout before taking it into another process - not always necessary, but sometimes useful.

Yep yep! And with that in mind, in a "real" workflow, you might not bother getting too close with the lasso, but rather just draw a rough outline maybe 20-50 pixels bigger than the object you're interested in.

So here's my example of using the magnetic lasso carefully over the top, combined with a rough outline around the bottom:

I just realized, since this is PS 101, that some folks might not realize how to switch among various tools that are put on the same spot on the toolbar. Just click and hold, and the options will appear.

For example, clicking and holding on the lasso will show this (the black square shows you which one you're using):

Message edited by author 2007-05-12 18:36:12.

slickchik

OM System OM-1

Olympus 12-40mm f/2.8 Pro

05/12/2007 06:36:38 PM · #12

Working with magnetic lasso:

Every time I make a small error in selecting, I try to go back and delete the last click but ctrl-d or ctrl-z deletes the entire selection. Am I doing something wrong? I want to be able to correct mistakes without losing the entire selection I was working on. Very frustrating.

Tamron SP AF 17-50mm f/2.8 Di II LD Aspherical (IF) for Nikon

05/12/2007 06:38:48 PM · #13

Originally posted by joynim:

Here's my first attempt but I'm going to go and try and get a better version

Very good. My comments to Di and Colette apply here, too.

Really, this is just an exercise to introduce these tools and demonstrate some of what they're good at and not so good at. The more advanced selection tools are where it gets really fun.

Speaking of which, by the time we're done, you'll be able to do things like multi-personality shots:

Nikon AF-S DX NIKKOR 18-200mm f/3.5-5.6G ED VR II

05/12/2007 07:07:28 PM · #14

Originally posted by slickchik:

I don't think there is any way to undo a last click in the middle of a selection - that's why the magnetic lasso is the most frustrating to me as well. :/

Prime_Time

Nikon D80

05/12/2007 07:47:19 PM · #15

Yea! I just got home from Denver. I will work on this weeks session when I get done mowing a foot high yard :-((

Apple iPhone

Sigma 24-70mm f/2.8 EX Aspherical DF for Nikon

05/12/2007 08:23:25 PM · #16

selecting about 3 pixels on his backside was fun! NOT!! so i ended up selecting the background on that side of him and feathered it to get rid of the line i think...

05/12/2007 09:13:52 PM · #17

Originally posted by Art Roflmao:

Just holding SHIFT while using one of the selection tools starts a new selection (while the other one is still visible). How do you adjust the selection line once it's complete?

05/13/2007 01:19:39 AM · #18

Originally posted by cpanaioti:

Just holding SHIFT while using one of the selection tools starts a new selection (while the other one is still visible). How do you adjust the selection line once it's complete?

Not sure what you mean by "adjust" - I just use shift and alt to add and subtract. But you can use and adjust paths - although I never use that.

05/13/2007 02:36:31 AM · #19

Originally posted by Art Roflmao:

Originally posted by cpanaioti:
Just holding SHIFT while using one of the selection tools starts a new selection (while the other one is still visible). How do you adjust the selection line once it's complete?

Not sure what you mean by "adjust" - I just use shift and alt to add and subtract. But you can use and adjust paths - although I never use that.

I tried shift but it always expected a complete loop. All I want to do is change where the path goes.

05/13/2007 02:49:20 AM · #20

Originally posted by cpanaioti:

Originally posted by Art Roflmao:

Originally posted by cpanaioti:
Just holding SHIFT while using one of the selection tools starts a new selection (while the other one is still visible). How do you adjust the selection line once it's complete?

Not sure what you mean by "adjust" - I just use shift and alt to add and subtract. But you can use and adjust paths - although I never use that.

I tried shift but it always expected a complete loop. All I want to do is change where the path goes.

OK - - I messed around and found this:
- Right click on your selection and choose "Make a Work Path" with a tolerance of 2.0
- Choose the Direct Selection tool ('A' - the White Arrow)
- Click on the path and you will see the square handle points show up. You can click on those and you will see some bezier handles appear which you can use to drag and reshape the path.
- You can also use the Pen tool to add and manipulate anchor points and reshape the path
- When you have it the way you want, you can right click on the path again and choose "Make Selection"

That's a bit more advanced and still is probably more hassle than some other methods, but I can see it being useful in certain situations.

05/13/2007 02:51:24 AM · #21

Originally posted by Art Roflmao:

Originally posted by cpanaioti:

Originally posted by Art Roflmao:

Originally posted by cpanaioti:
Just holding SHIFT while using one of the selection tools starts a new selection (while the other one is still visible). How do you adjust the selection line once it's complete?

Not sure what you mean by "adjust" - I just use shift and alt to add and subtract. But you can use and adjust paths - although I never use that.

I tried shift but it always expected a complete loop. All I want to do is change where the path goes.

OK - - I messed around and found this:
- Right click on your selection and choose "Make a Work Path" with a tolerance of 2.0
- Choose the Direct Selection tool ('A' - the White Arrow)
- Click on the path and you will see the square handle points show up. You can click on those and you will see some bezier handles appear which you can use to drag and reshape the path.
- You can also use the Pen tool to add and manipulate anchor points and reshape the path
- When you have it the way you want, you can right click on the path again and choose "Make Selection"

That's a bit more advanced and still is probably more hassle than some other methods, but I can see it being useful in certain situations.

Thank you!!! That's exactly what I was looking for. I can see this being very tedious unless you just have a few points to correct.

Message edited by author 2007-05-13 02:52:48.

Nikon AF-S DX NIKKOR 18-200mm f/3.5-5.6G ED VR II

05/13/2007 03:08:56 AM · #22

And now for the second part of this topic...

MASKS

For this part of the topic, I am going to cheat a little and copy/paste some info directly from the PS help file.

Originally posted by Adobe Photoshop CS Help File - About Masks:

Masks let you isolate and protect areas of an image as you apply color changes, filters, or other effects to the rest of the image. When you select part of an image, the area that is not selected is "masked" or protected from editing. You can also use masks for complex image editing such as gradually applying color or filter effects to an image.

Masks and channels are grayscale images, so you can edit them like any other image. With masks and channels, areas painted black are protected, and areas painted white are editable. Masks let you save and reuse time-consuming selections as alpha channels. Alpha channels can store selections so you can use them again, or you can load a saved selection into another image.

Photoshop lets you create masks in the following ways:

Quick Mask mode

Lets you edit any selection as a mask. The advantage of editing your selection as a mask is that you can use almost any Photoshop tool or filter to modify the mask. For example, if you create a rectangular selection with the Marquee tool, you can enter Quick Mask mode and use the paintbrush to extend or contract the selection, or you can use a filter to distort the edges of the selection. You can also use selection tools, because the quick mask is not a selection. (See Using Quick Mask mode to make selections (Photoshop).) You can also save and load selections you make using Quick Mask mode in Alpha channels.

Alpha channels

Lets you save and load selections. You can edit Alpha channels using any of the editing tools. When a channel is selected in the Channels palette, foreground and background colors appear as grayscale values.

Layer masks and vector masks let you produce a mix of soft and hard masking edges on the same layer. By making changes to the layer mask or the vector masks, you can apply a variety of special effects.

The only thing I am going to add is my endorsement of Quickmask mode - I only recently started using it and it is great for doing detailed selection work.

The only assignment on this part of the topic is to experiment with it.

Remember "Q" takes you into quickmask mode and also toggles you back out. When in Quickmask mode, the masked part of the image (UNselected part) is the colored part - you paint the mask in with a pencil or brush. If your brush opacity is less than 100% when masking, whatever you do to the resulting selection will be applied accordingly.

--------------------------
**Don't worry if you are one of the group members and are just catching up with the thread - feel free to apply the use of quickmask mode to the original assignment and see if it makes things easier than the lasso tool. I won't be posting the next topic for a few days, so go ahead and experiment, post experiences, discuss, tawk amongst yuhselves. :)

Prime_Time

Nikon D80

05/13/2007 09:57:09 AM · #23

Ok I am back, my yard was a monster to cut, but I am still the undisputed champ :-P Here is my school work :-)