How to Use Image Masks and Transparent Overlays in OBS
An Image Mask/Blend filter controls which parts of a source remain visible. Use it for a shaped camera view, such as a circle or rounded opening, while keeping an overlay or border as a separate image when needed.
A transparent overlay placed above your camera does not automatically hide the parts of the camera outside its opening. A mask can do that.
Prepare the mask image
Decide which part of the picture should stay visible. A mask with an alpha channel uses transparency to describe that area: opaque parts retain the source and transparent parts hide it.
A color-channel mask uses image values differently. Choose the filter mode that matches how the mask was made rather than assuming every downloaded black-and-white image uses the same setup.
Use an image with proportions suitable for your camera layout. Stretching the mask can change the shape you intended.
Apply the mask
- 1.Right-click the camera or other visual source in Sources.
- 2.Select Filters.
- 3.Under Effect Filters, click + → Image Mask/Blend.
- 4.Select the appropriate mask Type.
- 5.Browse to your mask file using Path.
- 6.Check the result in the preview and adjust the relevant filter properties.
For a mask based on a PNG's transparency, choose Alpha Mask (Alpha Channel). If the wrong parts disappear, check the mask type and the image's actual transparency before changing several settings.
Add a border or decoration separately
Add an Image source for a decorative frame and place it above the camera in the Sources list. Position the frame and masked camera together.
This keeps the camera's visible area separate from its decorative design. It also makes it easier to change the border without rebuilding the mask.
Check framing while moving
A mask can hide hands, hair, or other details as you move. Record a short sample using your normal position and movement, not just a still pose.
If the mask looks distorted, inspect its proportions and the filter's Stretch Image option. If the entire source disappears, temporarily disable the filter to confirm that the camera itself still works.
Remember that source filters apply to that source wherever it is reused. Test a shared camera's other scenes before changing its mask during a live session.