Hundreds of tutorials have been written on how to cut out a subject from a background in Photoshop, but Picture Instruments claims you can do a better job with its Chroma Mask application. Chroma Mask automates much of the process and adds a unique feature: mask as you shoot.
Chroma Mask is based on the practice of shooting a subject in front of a blue or green screen. It is common in broadcasting, e.g. the weatherman in front of the background made up of a map with a moving representation of isobars and weather symbols. In photography masking is often done by placing a person or object in front of an evenly lit white backdrop. That won’t work with Chroma Mask. The backdrop must be either blue, green or red. Red is only useful when shooting objects. Blue and green screen can be used when shooting people.
Masking is always the most difficult when it involves “fluff” — hair, feathers, small fibres, fur, etc. Most digital masking tools allow you to deal with these difficult elements by painting on the pixel level. Automation usually fails. Much to my surprise, Chroma Mask was exceptionally good at recognising and masking fluff.
The app succeeded at accurately recognising the hair, even when it’s heavily tinted by the background colour. But Chroma Mask did not cut out these small areas a full 100%. Because of that, you still have to go in and adjust the mask as with other apps. In Chroma Mask, you get two handles on a histogram to start with. If that’s not working, you can paint with brushes. This takes time, but works in the end. However, getting rid of colour spillage is another matter. The hairs with a distinct blue colour remained bluish after adjusting the colour correction knob slightly. Cranking up the “correction” made the colour more greenish — but it never got neutral grey.
Of course there’s a remedy: you just go to Photoshop and select all of the hair, then crank down the saturation until it barely has any colour left and you’re done, but that sort of breaks Chroma Mask’s biggest appeal.
What makes Chroma Mask unique
Robin Ochs, the lead developer at Picture Instruments, has a soft spot for somewhat unusual, dark interfaces and Chroma Mask is no exception. It’s not my taste, but the interface is relatively easy to understand. You load the image that has the subject you want to cut out, set screen options, load an optional colour LUT so the cut-out image will blend in better with your target background, and fine-tune the mask with the mask editing tools. You (optionally) load a new background and you’re ready to export.
However, some features are awkward to use. Mildly fiddly is the fact that brushes cannot be resized, nor changed from rounded to square. Instead, you can only zoom in and out of the image to create smaller brush selections. Scaling is fiddly too, as it can only be done by turning the rotary knob, not by setting the numbers in the box — but you can use the mouse wheel with or without modifier keys.
On the bright side and what sets Chroma Mask apart from everything else I’ve seen in this market, is the ability to set a watch folder and apply the entire masking workflow of your “prototype” image, to all images you shoot.
This is where Chroma Mask shines, because masking every subsequent image you shoot without having to go in and fix things on a per-image basis saves a lot of time. The only limitation here is that you need a fully controlled environment — a studio — to make sure every image you shoot will have the same lighting and the same backdrop.
Chroma Mask’s trick is that it saves all of your settings — including your mask painting — to a “.brush” file for later use. When you start shooting photos with the same setup as the first one, the app applies the settings of the first one to all subsequent images you save to the folder you designate as a watch folder in the app. Needless to say, this allows you to shoot tethered and mask on a continuous basis.
All of this has been so cleverly implemented that even if you crop the foreground “prototype” image tightly, you can still select an output option that will automatically add transparent space to fit the final background or scene you want to place your subject into.
Chroma Mask costs approx. €168.50.