Selection tools have many uses. They can be used to help with creating masks, cut out sections of an image, make effects only apply to the selected area and be used to move parts of an image.
This tutorial will explain the different selection tools available, show how they can be used to help create masks and also an advanced masking technique that can be very accurate and fast.
All the selection tools shown in this tutorial are for Photoshop Elements. These same tools are available in the full version of Photoshop as well.
Different selection tools
The different selection tools available are:
○ Marquee shapes – rectangular and elliptical in elements. CS also has single row and single column
○ lasso’s – 3 kinds of these. Normal, Polygonal and Magnetic
○ Magic wand
○ Quick selection
○ Selection brush – called quick mask in CS
First up is the marquee shapes.
These are the most simple of the selection tools. You choose your shape type, then by clicking and dragging, create the selection. If you haven’t used a selection before, try making one such as in the picture above. Then use the paint brush to colour it in. You will notice you can only colour the area that has been selected. Also try selecting the arrow tool. you will be able to drag and drop your selection where ever you want, effectively cutting it out from the image. You can even paste and copy it into other layers or images.
The lasso’s are a lot more accurate but take more skill to use. If cutting out complicated shapes then these should be your first port of call.
Standard lasso
Click and hold down your mouse button. Now move your mouse around and it will start drawing a selection line. When you release the button it will connect up to the starting point completing your selection.
Polygonal lasso
This is similar to the standard lasso except it creates a point when ever your click the button. So click once to give you a starting point. Then every time you click a new point will be created leaving a straight selection line between each click. This is useful for selecting areas with lots of straight lines.
Magnetic lasso
This one is rather clever. What it does is stick to the edges of things by detecting where the pixels change colour. In the picture above I selected round the ladybugs red shell. To do this, click once on a starting point. Then move your mouse carefully around the edge of the area you want to select. You should notice the selection is sticking to the edges of what you are selecting. You can manually insert additional points by clicking the button as you go. Also change the settings at the top (width, edge contrast and frequency) to adjust its sensitivity. To complete the selection you click on the starting point. It can be a bit odd to use at first but with a bit of practise you should find it a brilliant tool to start off selections.
Magic wand
This one is fantastic for selecting large areas of colour in a single click. If you click on a blue then it will select all the connected blue area that is within its tolerance. The higher the tolerance the more variations of that colour it will allow to be selected. So to select the red shell I set the tolerance to 50. Then, when I click on the red it selects all the reds within that range. You can then get it to select that same colour on the rest of the picture (parts that arn’t joined) by going to Select > Similar. This should now select everything on the page that’s within the tolerance you allowed. Very fast and very easy.
Quick selection
Another fast selection tool. This one you simply click and drag and the tool selects similar colours and tries to detect edges. Has mixed results. Sometimes it can make perfect selections straight away, other times it goes a bit wrong. Mainly depends on how much your subject contrasts with the background. High contrast selections should work great with this tool.
Selection brush
This one has 2 modes. In selection mode you literally paint on the selection. You can change this to mask mode (via the drop down menu ‘Mode:’ at the top of the window). In mask mode you will start painting in red. What you do here is to paint the parts of the image you don’t want to be selected. Then when you change it back the mode back to selection, all the areas not in red will be selected.
Selection tool tips
Once you have made a selection you can select the exact opposite by going Select > Inverse.
Once you have made a selection you can add extra parts to it by holding down the Shift key or delete parts by holding down the Alt key. When you hold either down, your selection tool should have a + or a – next to it to show you what it will do.
Under the ‘Select’ menu at the top of the screen there are a number of things you can do to your selection. For example you can ‘Grow’ your selection. All this does is increase its size slightly. You can also ‘Feather’ it. This will fade the edges which can creating nicer looking cut outs when making your own montages.
If I have a complex shape to select then i tend to start off with the magnetic tool to get a rough outline. When this is done I touch it up with the selection brush, adding and subtracting where needed.
The magic wand is also a personal favourite. Its a brilliant way of selecting large areas of similar colour fast. If can make cutting out a complex subject, such as a tree on a blue sky, very fast and easy.
You can save your selections by going Select > Save Selection. This means you can bring back that selection at any point by going Select > Load Selection.
Using selections to create masks
If you don’t know about masks I suggest you read the layers and their masks tutorial first.
Using a selection to create a mask is very simple. Insert a mask as normal. then create your selection using what ever method is best for the situation. Once your selection is made, select the mask. then fill the selected area in white. Then invert your selection, Select > Inverse, and fill the rest in black. That’s it.
Advanced Masking technique
This next masking technique is great for high contrast images or just getting a good starting point on you mask.
Create a new layer and place it at the bottom of the list, fill it in white. Then add a mask. You may wonder why the mask is in the wrong place in this image. Well it was just me being silly and forgetting to put it in the correct place. I correct it later on but you should set the mask up properly from the start to make it easier for you. Once your layers look like the image above (apart from the obvious mistake), select the image layer and press Ctrl A to select all. This will place a selection line around the whole image.
Press Ctrl C to copy the selection. Then hold down the Alt key and click on the mask. Your screen will turn white. What you are seeing is the mask itself. Press Ctrl V to past the selection into the mask. You will see a black and white image like in the image above.
Now press Ctrl I. This inverts the image so the blacks become white and the whites become black. The idea is the get the areas we want to be visible to become white and the areas to be hidden to become black. As you can see it has started to get closer to what we want.
Go to Enhance > Adjust Lighting > Levels.
Move the sliders under the histogram about until you have a made as much as possible of the area you want selected white and the area you want hidden black. If using the ladybird image set them to how they are in the image above. Click OK then select your image layer.
Most of the mask is now complete. All you need to do now is select the mask and touch it up using the brush tool as normal.
This technique can be very accurate with the right image. The more the main subject contrasts with the background the better. Try it out on a landscape photo where you want to replace the sky. The mask should hide all the sky even between leaves on trees which would otherwise take a long time to do with the brush tool.
