detail页面sketch支持镜像、detail图片合成由前端来做，但是新增sketch还是要过接口，sketch调整细节位置变更

src/tool/util.js

@@ -618,6 +618,60 @@ function segmentImage(markerImage,fullImage,size){
 		}
 	})
 }
+
+/**
+ * 处理PNG图片：透明度转白色，其他颜色转透明
+ * @param {string} sketchImage - 原始图片
+ * @returns {Promise} 处理后的ase64
+ */
+function sketchToMask(sketchImage) {
+	return new Promise((resolve, reject) => {
+		const img = new Image();
+		img.crossOrigin = 'anonymous';
+		img.onload = function() {
+			try {
+				const canvas = document.createElement('canvas');
+				const ctx = canvas.getContext('2d');
+				canvas.width = img.width;
+				canvas.height = img.height;
+				ctx.drawImage(img, 0, 0);
+				const imageData = ctx.getImageData(0, 0, canvas.width, canvas.height);
+				const data = imageData.data;
+				
+				for (let i = 0; i < data.length; i += 4) {
+					const r = data[i];
+					const g = data[i + 1];
+					const b = data[i + 2];
+					const a = data[i + 3];
+					if (a > 0) {
+						data[i] = 0;
+						data[i + 1] = 0;
+						data[i + 2] = 0;
+						data[i + 3] = 0;
+					} else {
+						// 完全透明的像素 -> 纯白色
+						data[i] = 255;
+						data[i + 1] = 255;
+						data[i + 2] = 255;
+						data[i + 3] = 255;
+					}
+				}
+				ctx.putImageData(imageData, 0, 0);
+				const base64 = canvas.toDataURL('image/png');
+				resolve(base64);
+				
+			} catch (error) {
+				reject(error);
+			}
+		};
+		
+		img.onerror = function() {
+			reject(new Error('图片加载失败'));
+		};
+		
+		img.src = sketchImage;
+	});
+}
 export {
   isEmail,
   getUploadUrl,
@@ -640,5 +694,6 @@ export {
   setGradual,
   calculateGradientCoordinate,
   segmentImage,
-  UrlToFile
+  UrlToFile,
+  sketchToMask
 }