Photoshop Masking & Compositing, by Katrin Eismann - Chapter 3 -The Essential Select

gluwater · March 21, 2006

Photoshop Masking & Compositing, by Katrin Eismann
Chapter 3, The Essential Select Menu

Chapter 3 describes the tools and options in the Select menu explaining how and when to use the specific tools. Even though we need to make selections in just about everything we do in PS most people never really delve into the Select Menu or understand the options held within.

The first four options in the Select menu are probaly the most used and should be accesed by their keyboard shortcuts to be more efficient.
They are:

Select All (Cmd + A) [noparse][Ctrl + A][/noparse]
Deselect (Cmd + D) [noparse][Ctrl + D][/noparse]
Reselect (Cmd + Shift + D) [noparse][Ctrl + Shift + D][/noparse]
Inverse (Cmd + Shift + I) [noparse][Ctrl + Shift + I][/noparse]

Select All does exactly what it states. It selects the entire active layer, active channel, or the entire document if it has only one layer. The example Katrin uses is one I never thought about before but makes sense. When making a composite you are usually only using parts of many images that have been placed in the same document. Photoshop keeps all the data of the image, even if it is outside of the canvas. To get rid of anything outside of the canvas to decrease your file size you can Select>Select All then Image>Crop to crop off all the image data outside the canvas. Before doing this I would be sure you will not need any of the data outside of the canvas.

Deselect can be a timesaver when using its keyboard shortcut. How many times have you needed to deselect an active selection and your current tool was not a selection tool, or you click outside the active selection just to accidentally create a new selection? I know I have. I never really thought of using the shortcut but it really does make sense to use it.

Many times when selecting many things at the same time it is easy to accidentally lose your selection and then you have to make it all over again right? Nope, just use Reselect and it will reselect the last active selection.

Inverse, when used with the magic wand can make complicated selections very easy as long as there is a solid easily defined backgound in the image. You just select the solid background with the magic wand and then use inverse to select your subject. Here is an example where I wanted to sharpen my friend without adding noise to the background. So I selected the background with the magic wand and then did an inverse to select him.

The next selection tool is Color Range. Katrin calls it "the smart Magic Wand". It allows you to make a selection similar to how the magic wand does but it gives you a preview of what you are selecting so you can get a more accurate initial selection. It is important to understand the options in the Color Range dialogue box to control your selection.

When you choose Select>Color Range Sampled Colors is choosen in the pull down menu at the top of the dialogue box . The foreground color is referenced and used to make the initial selection. This selection can then be changed by using the eyedroppers. The eyedropper on the left is used to make an initial selection. The middle eyedropper is used to add colors and the right eyedropper is used to subtract colors. Instead of haveing to switch between eyedroppers you can just select the left eyedropper and Shift + click to add colors or Alt + click to subtract colors. When in Color Range, by right clicking you can change the sample size of the eyedropper to point sample, 3x3 average, or 5x5 average.

The Fuzziness slider is often mistaken for Tolerance like in the magic wand. They are similar but in it not only controls which pixels will be selected it also controls how much of a pixel will be selected to give more realistic color and tonal transitions. To make accurate color selections Katrin suggests to use a smaller fuzziness setting and sample often when selecting large areas of similar color. When selecting more complex areas of color use a larger fuzziness and select fewer points.

The Selection Preview has 5 options with the default being none.

Greyscale appears as if it was a channel mask.
Black Matte views with a black background.
White Matte views with a white background.
Quick Mask appears as it would in Quick Mask mode.

Each option can be useful with different images, play with them and find out which you prefer. The following screen shot shows what greyscale looks like selecting a yellow flower.

In the Color Range dialogue box in the Select drop down menu you can choose to select default colors. When you do this PS selects pixels with the majority of it being that color. Katrin uses the example of reducing the red from the face in a portrait with the help of a hue/saturation Adjustment Layer.

Grow and Similar
These two commands select like pixels in an image. They both require you to have an active selection and they use the tolerences set in the Magic Wand settings. They differ because grow only selects contiguous pixels where similar selects non-contiguous pixels based on color and tone throughout the image.

Feather
Feather softens the edges of a selection but has a big downfall. It does not give you a preview of how much it is feathering. Katrin gives a helpful alternative to the feather command, using Quick Mask and Gaussian Blur.

There is more to the chapter that I will add in the next couple of days, I just wanted to get something posted.

gluwater · March 31, 2006

Part 2
Smart Feather
Instead of using Feather on a selection you can use make a selection and then use Gaussian Blur on it. Using Gaussian Blur gives you the same effect as feather except it gives you a preview of what you are selecting. Here is an example using Gary as my selection. I made the selection using techniques explained in upcoming chapters. Once the selection is made go to Quick Mask Mode (press q) then select Filter>Blur>Gaussian Blur and you will have a preview of your Feather.

The Modify Menu
The Modify Menu contains 4 commands: Border, Smooth, Expand, and Contract. These commands can also be re-created using Quick Mask, filters, and tonal controls.

Border
When you have a selection already made you can select Select>Modify>Border and in the dialogue box you can choose the thickness of your border in pixels. Your selection will change into a border at the edge of your previous selection the thickness you chose. In this example I chose a border of 20 pixels. The border is 10 pixels inside the previous selection and 10 pixels outside the selection.

Smooth
Sometimes we all make selections that are not eactly smooth. The Smooth command will do exactly what it says, smooth it out. I selected part of this flower with the lasso tool and the edge is jagged. I used Select>Modify>Smooth and used a setting of 20 Pixels.

You can get the same effect by using the Filter>Noise>Median Filter combined with Quick Mask.

Expand and Contract
These are especially useful for getting rid of Halos around selections. If you have to much selected or not enough than these are the tools to use. They can be reproduced by using the filters Filter>Other>Maximum and Filter>Other>Minimum in Quick Mask mode. In the following I did not have enough selected so I used Contract to make my selection closer to the flower.

Using Curves to Expand and Contract Selections
To fine tune selections in Quick Mask Curves can be helpful. If you want to slightly expand or contract your mask you can use the midtones in curves to change the mask. Once you are in Quick Mask mode and have your mask created you can adjust the midtones in curves to refine the mask.

I have a little to much selected.

Now I use Curves to Contract the mask slightly.

Transform Selection
This item in the Select Menu gives you the same options as Edit>Free Transform does. You can Scale, Rotate, Skew, Distort, Perspective, Warp, Flip Horizontal or Vertical. It can be useful for adding things such as a drop shadow.

Save and Load Selection
Once you have made a selection you will definitely want to save it, especially if it is an intricate time consuming selection. Two ways to save a selection are to use Select>Save Selection or to click Save Selection as Channel in the Channels Palette. Either way is doing the same thing, creating a new channel with your selection data.
To load a saved selection or channel you can use Select>Load Selection or click on Load Channel as Selection in the Channels Palette.

One thing to note is that when you save your file as anything besides a PSD or TIFF you lose all your channels so you also lose any saved selections you had. To save a selection to different file than you are currently working on is to Select the channel you need to duplicate, select Duplicate Channel in the Channels palette flyout menu, then make sure New is selected from the pull down menu name the file and click OK.

Conclusion
The Select Menu has some great tools to help with refineing your selections, but remember there are slternate methods to acheive the same results. Play around with the tools and before you know it you will be selecting things just for the fun of it, well maybe not but it will become much easier.

jfriend · March 31, 2006

Awesome writeup Nick - thanks!

gluwater wrote:

Conclusion
The Select Menu has some great tools to help with refineing your selections, but remember there are slternate methods to acheive the same results. Play around with the tools and before you know it you will be selecting things just for the fun of it, well maybe not but it will become much easier.

Awesome writeup Nick - thanks! There were a bunch of things in here I didn't know. I much appreciate all the examples you put in. I know from my own writeups that the examples can be very time consuming.

While I've used gaussian blur on masks to blur edges or to grow/shrink them, I didn't realize you could do the same on a selection in quick mask mode. That makes sense I guess.

I also didn't realize Photoshop had the border command for selections. I've done this manually by saving a selection, expanding it, saving that, contracting it, then intersecting the two selections. The border command is a ton easier.

Have you used selecting based on color range? That's one I've never used and I'm wondering what kind of images it would be useful on? When is it more useful than the magic wand for example?

pathfinder · March 31, 2006

I use the Select Color Range more frequently than the Magic Wand, which selects pixels by intensity in the three channels, but does not partially select a pixel as the Select Color Range command can.

Hence the Magic wand either selects pixels or not, but the Color Range Select command gives graduated, smoother selections with grey edges on the mask.

The Select Color Range command is very useful for the greens of vegetation, or the blues of the sky, or the reds of a face. As I demonstrated here http://www.dgrin.com/showthread.php?t=29656

The author uses the the Select Color Range command to select the red pixels in a portrait that looked too red like sunburn or IR burn, and then dialed back the intensity in an adjustment layer to help correct the ruddiness of the portrait. Kind of a neat trick.

Very nice write up Nick. Well done!!

jfriend · March 31, 2006

Select color range works surprisingly well on some images

pathfinder wrote:

I use the Select Color Range more frequently than the Magic Wand, which selects pixels by intensity in the three channels, but does not partially select a pixel as the Select Color Range command can.

Hence the Magic wand either selects pixels or not, but the Color Range Select command gives graduated, smoother selections with grey edges on the mask.

The Select Color Range command is very useful for the greens of vegetation, or the blues of the sky, or the reds of a face. As I demonstrated here http://www.dgrin.com/showthread.php?t=29656

The author uses the the Select Color Range command to select the red pixels in a portrait that looked too red like sunburn or IR burn, and then dialed back the intensity in an adjustment layer to help correct the ruddiness of the portrait. Kind of a neat trick.

Very nice write up Nick. Well done!!

I didn't realize the difference in how the magic wand and select color range work - particularly the partial pixel selection part. Fortunately I don't use the magic wand much anymore, but it sounds like I should start using select color range more often.

I often pull a copy of a channel and apply a curve to it to isolate something in a particular color, but it sounds like color range gives you some additional capabilities over that since it isn't just restricted to R, G and B. I just played with select color range on a few images and it works really well for making rough selections on some images. I'll be using this one more often.

gluwater · March 31, 2006

Thanks for the kind words about the write up guys. I really learned a lot more doing the write up than I would have otherwise. I think one of the best things I learned in this chapter was Select Color range. I never really understood how it worked before and I think I will use it much more now. Making the samples really helped me learn how to use masks and chanels more effectively. I have to say that I am really liking this book.

gluwater · March 31, 2006

Anyone recognize the photographer?

jfriend · March 31, 2006

You do have to learn it before you can teach it

gluwater wrote:

Thanks for the kind words about the write up guys. I really learned a lot more doing the write up than I would have otherwise. I think one of the best things I learned in this chapter was Select Color range. I never really understood how it worked before and I think I will use it much more now. Making the samples really helped me learn how to use masks and chanels more effectively. I have to say that I am really liking this book.

Yeah, the best thing about volunteering to write up a chapter is that you ARE going to really learn that chapter while figuring out how to explain it. That's what I found when I did a chapter on the LAB book and it's why I picked a chapter for this book too. I guess this is a case where you do have to learn it before you can teach it.

Thanks again for doing the writeup.

pathfinder · April 2, 2006

gluwater wrote:

Anyone recognize the photographer?

SO... who is the shooter, Nick?

gluwater · April 3, 2006

pathfinder wrote:

SO... who is the shooter, Nick?

Our very own dragon300zx. You were there Jim, well not in the woods with us, but this was taken at Mackinaw.

pathfinder · April 3, 2006

I should have known:uhoh . I think I have a similar image from Yosemite.

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Photoshop Masking & Compositing, by Katrin Eismann - Chapter 3 -The Essential Select

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