diff --git a/src/api/douyin.ts b/src/api/douyin.ts
index ce9b5f9..94be850 100644
--- a/src/api/douyin.ts
+++ b/src/api/douyin.ts
@@ -4,7 +4,11 @@ const PREFIX = 'douyin'
 
 function normalizeOssUrl(url: string) {
   if (!url) return ''
-  return String(url).replace(/\\u0026/gi, '&').replace(/\\u003d/gi, '=')
+  let s = String(url).replace(/\\u0026/gi, '&').replace(/\\u003d/gi, '=').trim()
+  // 真机 https 页加载 http 图会被拦截，统一升 https
+  if (s.indexOf('//') === 0) s = `https:${s}`
+  if (/^http:\/\//i.test(s)) s = `https://${s.slice(7)}`
+  return s
 }
 
 function guessContentType(file: File | Blob, filename?: string) {
diff --git a/src/views/douyin/components/ImagePointCloud.vue b/src/views/douyin/components/ImagePointCloud.vue
index ed59c3b..528f091 100644
--- a/src/views/douyin/components/ImagePointCloud.vue
+++ b/src/views/douyin/components/ImagePointCloud.vue
@@ -186,9 +186,9 @@ function preloadResult(url: string) {
   if (!url || !renderer || !sm) return
   resultKey = url
   sm.setResultPreloadStatus('loading')
-  // 效果图保留完整画面做点云（去背景会在手机上采空，表现为「没有效果图点云」）
+  // 效果图点云去掉背景，只保留主体
   renderer.textures
-    .load(url, { removeBackground: false })
+    .load(url, { removeBackground: true })
     .then((entry: any) => {
       if (destroyed || !sm) return
       if (!entry || !entry.pointCloudBuffer) {
@@ -428,14 +428,16 @@ onUnmounted(() => {
   opacity: 0;
 }
 
+/* 仅占位；真实采样已改用离屏 canvas，勿再用 CSS 锁尺寸 */
 .ipc-scale {
   position: absolute !important;
-  width: 1px !important;
-  height: 1px !important;
+  left: -9999px !important;
+  top: 0 !important;
+  width: 2px;
+  height: 2px;
   opacity: 0;
   pointer-events: none;
-  left: -9999px !important;
-  top: auto !important;
+  visibility: hidden;
 }
 
 .ipc-fallback {
diff --git a/src/views/douyin/components/image-point-cloud/point-cloud-sampler.js b/src/views/douyin/components/image-point-cloud/point-cloud-sampler.js
index 9a31997..0a7a87f 100644
--- a/src/views/douyin/components/image-point-cloud/point-cloud-sampler.js
+++ b/src/views/douyin/components/image-point-cloud/point-cloud-sampler.js
@@ -46,11 +46,11 @@ function createPointCloudSampler(scaleCanvas, viewportW, viewportH, sharedCtx) {
     const forceSampleSize = options.forceSampleSize || null
 
     const image = entry.image
-    if (!image || !image.width || !image.height) {
+    const srcW = (image && (image.naturalWidth || image.width)) || 0
+    const srcH = (image && (image.naturalHeight || image.height)) || 0
+    if (!image || !srcW || !srcH) {
       throw new Error('image not ready for sampling')
     }
-    const srcW = image.width
-    const srcH = image.height
     let w
     let h
     if (forceSampleSize && forceSampleSize.width && forceSampleSize.height) {
@@ -152,13 +152,20 @@ function createPointCloudSampler(scaleCanvas, viewportW, viewportH, sharedCtx) {
           const dg = g - bgG
           const db = b - bgB
           const distance = Math.sqrt(dr * dr + dg * dg + db * db) / 441.67
-          const notBackground = Math.max(0, Math.min(1, (distance - 0.025) / 0.09))
+          const softKnockout = !!options.softKnockout
+          // 默认更狠地抠掉接近四角背景色的点；softKnockout 略放宽防采空
+          const distCut = softKnockout ? 0.028 : 0.05
+          const distRamp = softKnockout ? 0.08 : 0.07
+          if (distance < distCut) continue
+          const notBackground = Math.max(0, Math.min(1, (distance - distCut) / distRamp))
           const chroma = Math.abs(r - g) + Math.abs(g - b) + Math.abs(r - b)
-          const nearBlack = lum < 0.07 && chroma < 16
-          if (nearBlack) continue
-          const darkKeep = Math.max(0, Math.min(1, (0.62 - lum) / 0.45))
-          const softKeep = Math.max(0, Math.min(1, (distance - 0.015) / 0.07))
-          presence = Math.max(notBackground, darkKeep * 0.5, softKeep * 0.4) * a
+          const bgLum = luminance(bgR, bgG, bgB)
+          // 仅亮底时丢弃近黑噪点，避免黑底效果图误杀主体暗部
+          if (bgLum > 0.35) {
+            const nearBlack = lum < 0.07 && chroma < 16
+            if (nearBlack) continue
+          }
+          presence = notBackground * a
           subjectWeight = 1
         }
 
diff --git a/src/views/douyin/components/image-point-cloud/webgl/renderer.js b/src/views/douyin/components/image-point-cloud/webgl/renderer.js
index 5af4ed5..95fe1b7 100644
--- a/src/views/douyin/components/image-point-cloud/webgl/renderer.js
+++ b/src/views/douyin/components/image-point-cloud/webgl/renderer.js
@@ -235,11 +235,41 @@ function createRenderer(canvas, cssW, cssH, dpr, scaleCanvas) {
     gl.clear(gl.COLOR_BUFFER_BIT)
 
     const pointOpacity = u.opacity != null ? u.opacity : 1
+    const reveal = u.reveal != null ? u.reveal : 0
 
-    // 完整效果图改由页面层按预览框位展示，避免 WebGL 全屏图与预览错位
-    if (pointOpacity > 0.001 && cloudA && cloudB) {
-      gl.enable(gl.BLEND)
-      gl.blendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
+    gl.enable(gl.BLEND)
+    gl.blendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA)
+
+    // 揭示阶段绘制效果图纹理，避免点云淡出后整页黑屏
+    if (hasResult && reveal > 0.001 && resultTex) {
+      const fit = containFit(contentAspect || 1, cssW, cssH, 0.98)
+      gl.useProgram(quadProgram)
+      gl.activeTexture(gl.TEXTURE0)
+      gl.bindTexture(gl.TEXTURE_2D, resultTex)
+      gl.uniform1i(quadUni.uTexture, 0)
+      gl.uniform1f(quadUni.uOpacity, Math.min(1, reveal))
+      gl.uniform2f(quadUni.uContentScale, fit.scaleX, fit.scaleY)
+      gl.uniform2f(quadUni.uContentOffset, fit.offsetX, fit.offsetY)
+      gl.uniform4f(
+        quadUni.uBgColor,
+        VISUAL.STAGE_BG[0],
+        VISUAL.STAGE_BG[1],
+        VISUAL.STAGE_BG[2],
+        1
+      )
+      gl.bindBuffer(gl.ARRAY_BUFFER, quadBuffer)
+      if (quadAttr.aPosition >= 0) {
+        gl.enableVertexAttribArray(quadAttr.aPosition)
+        gl.vertexAttribPointer(quadAttr.aPosition, 2, gl.FLOAT, false, 16, 0)
+      }
+      if (quadAttr.aUv >= 0) {
+        gl.enableVertexAttribArray(quadAttr.aUv)
+        gl.vertexAttribPointer(quadAttr.aUv, 2, gl.FLOAT, false, 16, 8)
+      }
+      gl.drawArrays(gl.TRIANGLE_STRIP, 0, 4)
+    }
+
+    if (pointOpacity > 0.001 && cloudA && cloudB && cloudA.buffer && cloudB.buffer) {
       gl.useProgram(pointProgram)
 
       bindCloudAttribs(
diff --git a/src/views/douyin/components/image-point-cloud/webgl/texture-manager.js b/src/views/douyin/components/image-point-cloud/webgl/texture-manager.js
index 00c702e..4ba791c 100644
--- a/src/views/douyin/components/image-point-cloud/webgl/texture-manager.js
+++ b/src/views/douyin/components/image-point-cloud/webgl/texture-manager.js
@@ -14,23 +14,27 @@ function createTextureManager(gl, canvas, scaleCanvas, viewportW, viewportH) {
   let maxTexSize = VISUAL.MAX_TEX_SIZE
   let maxPoints = POINT_CLOUD.MEDIUM
   let sampleSide = POINT_CLOUD.SAMPLE_MEDIUM
-  let scaleCtx = null
 
-  if (scaleCanvas) {
+  /**
+   * 真机关键：不要用 DOM 里被 CSS 锁成 1×1 的 canvas 做 getImageData。
+   * 部分 WebView 会把绘图缓冲钳到 CSS 尺寸，导致效果图采点为空 → 整页黑屏。
+   */
+  const sampleCanvas = document.createElement('canvas')
+  let scaleCtx = null
+  try {
+    scaleCtx = sampleCanvas.getContext('2d', { willReadFrequently: true })
+  } catch (e) {
     try {
-      // getImageData 频繁读回：声明 willReadFrequently 消除告警并提升性能
-      scaleCtx = scaleCanvas.getContext('2d', { willReadFrequently: true })
-    } catch (e) {
-      try {
-        scaleCtx = scaleCanvas.getContext('2d')
-      } catch (e2) {
-        scaleCtx = null
-      }
+      scaleCtx = sampleCanvas.getContext('2d')
+    } catch (e2) {
+      scaleCtx = null
     }
   }
+  // 保留入参 scaleCanvas 作兼容，实际采样/缩放一律走离屏 canvas
+  void scaleCanvas
 
   const sampler = createPointCloudSampler(
-    scaleCanvas,
+    sampleCanvas,
     viewportW,
     viewportH,
     scaleCtx
@@ -114,11 +118,20 @@ function createTextureManager(gl, canvas, scaleCanvas, viewportW, viewportH) {
     }
   }
 
+  function normalizeImageSrc(src) {
+    let s = String(src || '').trim()
+    if (!s) return ''
+    if (s.indexOf('//') === 0) s = 'https:' + s
+    if (/^http:\/\//i.test(s)) s = 'https://' + s.slice(7)
+    return s
+  }
+
   /**
    * 加载图片并严格在 onload 之后再交给后续逻辑。
    * http(s) 优先 fetch→blob，避免手机 WebView 跨域导致 getImageData 采点失败。
    */
-  function loadImage(src) {
+  function loadImage(rawSrc) {
+    const src = normalizeImageSrc(rawSrc)
     return new Promise(function (resolve, reject) {
       if (!src) {
         reject(new Error('empty src'))
@@ -136,8 +149,8 @@ function createTextureManager(gl, canvas, scaleCanvas, viewportW, viewportH) {
           if (settled) return
           setTimeout(function () {
             if (settled) return
-            const w = img.width || 0
-            const h = img.height || 0
+            const w = img.naturalWidth || img.width || 0
+            const h = img.naturalHeight || img.height || 0
             if (!w || !h) {
               settled = true
               if (revokeUrl) {
@@ -173,15 +186,36 @@ function createTextureManager(gl, canvas, scaleCanvas, viewportW, viewportH) {
 
       // 远程图：先 blob 同源化，再采样（手机端效果图点云依赖此路径）
       if (/^https?:\/\//i.test(src) && typeof fetch === 'function') {
-        fetch(src, { mode: 'cors', credentials: 'omit', cache: 'force-cache' })
+        fetch(src, { mode: 'cors', credentials: 'omit', cache: 'no-cache' })
           .then(function (res) {
             if (!res || !res.ok) throw new Error('fetch image http ' + (res && res.status))
             return res.blob()
           })
           .then(function (blob) {
             if (!blob || !blob.size) throw new Error('empty image blob')
+            // createImageBitmap 在部分 WebView 上更稳，再回退 blob URL
+            if (typeof createImageBitmap === 'function') {
+              return createImageBitmap(blob).then(function (bitmap) {
+                if (bitmap && bitmap.width && bitmap.height) {
+                  resolve({
+                    image: bitmap,
+                    path: src,
+                    width: bitmap.width,
+                    height: bitmap.height,
+                    revokeUrl: '',
+                  })
+                  return null
+                }
+                throw new Error('empty bitmap')
+              }).catch(function () {
+                const objUrl = URL.createObjectURL(blob)
+                bindImage(objUrl, objUrl)
+                return null
+              })
+            }
             const objUrl = URL.createObjectURL(blob)
             bindImage(objUrl, objUrl)
+            return null
           })
           .catch(function () {
             // CORS 拉流失败时退回 <img crossOrigin>
@@ -195,11 +229,11 @@ function createTextureManager(gl, canvas, scaleCanvas, viewportW, viewportH) {
   }
 
   function uploadTexture(image, path) {
-    if (!image || !image.width || !image.height) {
+    if (!image || !(image.width || image.naturalWidth) || !(image.height || image.naturalHeight)) {
       throw new Error('uploadTexture: image not ready')
     }
-    const srcW = image.width || 1
-    const srcH = image.height || 1
+    const srcW = image.naturalWidth || image.width || 1
+    const srcH = image.naturalHeight || image.height || 1
     let drawW = srcW
     let drawH = srcH
     const longest = Math.max(srcW, srcH)
@@ -212,9 +246,9 @@ function createTextureManager(gl, canvas, scaleCanvas, viewportW, viewportH) {
     const tex = createEmptyTexture()
     gl.bindTexture(gl.TEXTURE_2D, tex)
     try {
-      if ((drawW !== srcW || drawH !== srcH) && scaleCanvas && scaleCtx) {
-        scaleCanvas.width = drawW
-        scaleCanvas.height = drawH
+      if ((drawW !== srcW || drawH !== srcH) && sampleCanvas && scaleCtx) {
+        sampleCanvas.width = drawW
+        sampleCanvas.height = drawH
         scaleCtx.clearRect(0, 0, drawW, drawH)
         scaleCtx.drawImage(image, 0, 0, drawW, drawH)
         gl.texImage2D(
@@ -223,7 +257,7 @@ function createTextureManager(gl, canvas, scaleCanvas, viewportW, viewportH) {
           gl.RGBA,
           gl.RGBA,
           gl.UNSIGNED_BYTE,
-          scaleCanvas
+          sampleCanvas
         )
       } else {
         gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, image)
@@ -331,11 +365,23 @@ function createTextureManager(gl, canvas, scaleCanvas, viewportW, viewportH) {
         entry.height = uploaded.height
         entry.aspect = uploaded.aspect
 
-        const cloud = sampler.sample(entry, {
+        let cloud = sampler.sample(entry, {
           maxPoints: maxPoints,
           maxSide: sampleSide,
           removeBackground: removeBackground,
         })
+        // 采点过稀：降分辨率再采，仍保持去背景（效果图不要背景点云）
+        if (!cloud || cloud.count < Math.max(40, maxPoints * 0.01)) {
+          cloud = sampler.sample(entry, {
+            maxPoints: maxPoints,
+            maxSide: Math.min(sampleSide, POINT_CLOUD.SAMPLE_LOW),
+            removeBackground: removeBackground,
+            softKnockout: true,
+          })
+        }
+        if (!cloud || cloud.count < Math.max(80, Math.floor(maxPoints * 0.02))) {
+          throw new Error('point cloud sample too sparse: ' + (cloud && cloud.count))
+        }
         entry.pointCloud = cloud
         entry.pointCloudBuffer = uploadCloudBuffer(cloud)
         entry.preloadStatus = 'ready'