Selecting and rendering objects from their background can be a difficult skill to master. Nobody is inherently born with an understanding of Photoshop – it takes years of practice and lots of screw-ups to become even remotely good. Yet it seems that rendering and selecting an object always remains one of the most difficult tasks to incorporate into regular workflow.
In the past I covered a method of selecting objects using the Photoshop pen tool. Although it's always an option, the pen tool is traditionally considered to be the most complicated method. Excellent for advanced users but not perfect in every situation.
For this post I'll cover how to get into quick masking with Photoshop by creating selections around objects. Much like the pen tool, quick masking will feel a little wonky at first. But stick with it and soon you'll be rendering out images like it's nobody's business.
What better way to learn about a technique than through a step-by-step demonstration? To start off we should open a simple image in Photoshop and prepare it for quick mask mode. You can choose any image you like, so long as there's something that can be rendered out of the pink background. Some good resources can also be found on freevector.com.
I'll be using this pink flower which creates an excellent contrast against the green meadow. Once you've opened a document with your chosen photo we can dive in head-first!
Quick masking is done by creating two distinct areas: an area that is “selected”, and the other area which is not selected. When viewing the mask as a layer it only uses grayscale colors. Black is considered selected, white is not-selected, and gray behaves more like an opacity difference.
So to get started we can either quickly brush a mask over the image or we can use the quick selection tool. Let's go for the latter and start off with a quick selection.
With this tool active just click on different areas within the object you're rendering. In my case I want to render the pink flower petals, so I'll keep clicking until I have a very basic selection around the whole flower. Don't worry so much about precision because this won't be exactly perfect. We just need to create an initial selection which can then be refined in quick mask mode.
Entering Quick Mask
With a rough selection created the quick mask process should be 10x easier. To enter quick mask mode you can press the Q key as a keyboard shortcut, or locate the camera icon at the bottom of the toolbox. When hovering over the icon a tooltip should appear that reads “Edit in Quick Mask Mode”.
Once you're in quick mask the marching ant selection will disappear. Instead you'll have two distinct portions of the image – a normal-looking area which represents the selected content, along with a big red overlay. The red content is excluded from the selection.
If this color is too bright you can always change the settings by double-clicking on the quick mask camera icon in the toolbox. The 1st click will turn on/off quick mask mode and the 2nd click will bring up a settings window.
In these settings you're able to set the hue, color opacity, and the style of mask selection. By default the non-selected areas get the color(also known as masked areas). But you can change this setting so the selected areas get the color. It all depends how you want to work with the tool.
Refining a Selection
First I'm going to change the quick mask background color to a light blue. This will be easier to look at while editing the flower selection. Next I'm going to grab my brush tool and use the black foreground color to paint a mask onto some of the background.
While refining a selection you want to add a mask into the background while removing a mask from the object itself. The end result should be a 99% perfect selection around the object you want rendered away from the BG. To get into those tight edges you'll need to be constantly resizing your brush(keyboard shortcuts are the left and right brackets).
Once you feel the image has been refined enough just exit quick mask mode and check out the new selection. By default your main object should be the only thing selected which can now be cut into a new document, or removed from the background by deleting all other pixels.
The first option is easier if you already have a document which needs the rendered object. But in order to delete the entire background we need to accomplish one more step.
Removing the Background
I would say complete removal of a background is one of the most important parts of quick mask editing. Since almost every image has a background they all require a bit of finesse to get everything selected and removed just perfectly.
After exiting quick mask mode you'll have a selection around the object of your choice. If you press delete it'll just remove the object you want and you'll only be left with the background. Kinda the exact opposite of what we need.
Instead let's inverse the selection so that it encompasses all the other pixels. This can be achieved from the menu bar Select > Inverse or the keyboard shortcut SHIFT+CTRL+I.
Now when you press delete it'll clear everything except your main object. Pretty great right?
When I first started learning Photoshop one of the first techniques I learned was quick masking. It's an incredibly powerful technique that I continue to use now a decade later. Plus this type of masking can be applied to other techniques like filter and layer masks. Whenever you have some extra time be sure to fit in a little practice with quick masking. You might surprise yourself how easy the task becomes once you understand the whole process.