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VirtualBackground: Improved mask detection and reduced image artifacts #861

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Merged
davidliu merged 1 commit into from
Feb 8, 2026
Merged

VirtualBackground: Improved mask detection and reduced image artifacts #861

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5 changes: 5 additions & 0 deletions .changeset/friendly-forks-exist.md
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@@ -0,0 +1,5 @@
---
"client-sdk-android": patch
---

Make selfie segmenter work better
6 changes: 2 additions & 4 deletions ...rc/main/java/io/livekit/android/track/processing/video/VirtualBackgroundVideoProcessor.kt
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@@ -1,5 +1,5 @@
/*
* Copyright 2024-2025 LiveKit, Inc.
* Copyright 2024-2026 LiveKit, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
Expand Down Expand Up @@ -122,9 +122,7 @@ class VirtualBackgroundVideoProcessor(
val image = imageProxy.image

if (enabled && image != null) {
// Put 0 for rotation degrees
// We'll rotate it together with the original video frame in the shader.
val inputImage = InputImage.fromMediaImage(image, 0)
val inputImage = InputImage.fromMediaImage(image, imageProxy.imageInfo.rotationDegrees)
latch.acquire()
val task = segmenter.process(inputImage)
task.addOnSuccessListener { mask ->
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5 changes: 3 additions & 2 deletions ...cessors/src/main/java/io/livekit/android/track/processing/video/shader/CompositeShader.kt
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@@ -1,5 +1,5 @@
/*
* Copyright 2025 LiveKit, Inc.
* Copyright 2025-2026 LiveKit, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
Expand Down Expand Up @@ -29,13 +29,14 @@ uniform sampler2D background;
uniform samplerExternalOES frame;
uniform sampler2D mask;
out vec4 fragColor;
in vec2 vMaskCoords;

void main() {

vec4 frameTex = texture(frame, texCoords);
vec4 bgTex = texture(background, texCoords);

float maskVal = texture(mask, texCoords).r;
float maskVal = texture(mask, vMaskCoords).r;

// Compute screen-space gradient to detect edge sharpness
float grad = length(vec2(dFdx(maskVal), dFdy(maskVal)));
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4 changes: 3 additions & 1 deletion ...ors/src/main/java/io/livekit/android/track/processing/video/shader/DefaultVertexShader.kt
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Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
/*
* Copyright 2025 LiveKit, Inc.
* Copyright 2025-2026 LiveKit, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
Expand All @@ -18,12 +18,14 @@ package io.livekit.android.track.processing.video.shader

internal const val DEFAULT_VERTEX_SHADER_SOURCE = """#version 300 es
out vec2 texCoords;
out vec2 vMaskCoords;
in vec4 in_pos;
in vec4 in_tc;
uniform mat4 tex_mat;
void main() {
gl_Position = in_pos;
texCoords = (tex_mat * in_tc).xy;
vMaskCoords = vec2(in_tc.x, 1.0 - in_tc.y);
}
"""

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