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通过备案号查网站,荆州学校网站建设,建设网站基本步骤,网站自己做还是找公司目录1. 解决措施2. 示例代码3. 将arraybuffer转换成cv::mat4. 使用OH_PixelMap_AccessPixels获取PixelMap的内存地址#xff0c;将这个内存地址中的数据转换为cv::mat的1. 解决措施 将PixelMap转换成cv::mat有两种方法#xff1a; 将PixelMap的arraybuffer转换成cv::mat。使…目录1. 解决措施2. 示例代码3. 将arraybuffer转换成cv::mat4. 使用OH_PixelMap_AccessPixels获取PixelMap的内存地址将这个内存地址中的数据转换为cv::mat的1. 解决措施将PixelMap转换成cv::mat有两种方法将PixelMap的arraybuffer转换成cv::mat。使用OH_PixelMap_AccessPixels获取PixelMap的内存地址将这个内存地址中的数据转换为cv::mat。上述两种方法都需确保PixelMap的格式与OpenCV中Mat的格式一致否则会导致色彩偏差。2. 示例代码importcPixelMapToMatfromlibcpixelmaptomat.so;import{BusinessError}fromkit.BasicServicesKit;import{image}fromkit.ImageKit;Entry Component struct Index{State pixelMap:image.PixelMap|undefinedundefinedasyncarrayBufferToMat(){if(this.pixelMapundefined||this.pixelMap){letcontextthis.getUIContext().getHostContext()ascommon.UIAbilityContext;letresourceManagercontext.resourceManagerletimageArrayawaitresourceManager.getMediaContent($r(app.media.sample10));letpixelBuffernewUint8Array(imageArray).bufferasObjectasArrayBuffer console.info(pixelBuffer length: pixelBuffer.byteLength);letimageResourceimage.createImageSource(pixelBuffer);letopts:image.DecodingOptions{editable:true,desiredPixelFormat:image.PixelMapFormat.RGBA_8888}this.pixelMapawaitimageResource.createPixelMap(opts);}constreadBuffer:ArrayBuffernewArrayBuffer(this.pixelMap.getPixelBytesNumber());// Obtain the array buffer of the pixelmapconsole.info(readBuffer length: readBuffer.byteLength);this.pixelMap.readPixelsToBuffer(readBuffer).then((){console.info(No Error!)}).catch((err:BusinessError){console.error(Error! err.message)})constdirgetContext(this).filesDir;console.info(save path: dir);cPixelMapToMat.arrayBufferToMat(this.pixelMap,readBuffer,dir);}asyncaccessToMat(){if(this.pixelMapundefined||this.pixelMap){letresourceManagergetContext(this).resourceManagerletimageArrayawaitresourceManager.getMediaContent($r(app.media.sample14));letpixelBuffernewUint8Array(imageArray).bufferasObjectasArrayBuffer console.info(pixelBuffer length: pixelBuffer.byteLength);letimageResourceimage.createImageSource(pixelBuffer);letopts:image.DecodingOptions{editable:true,desiredPixelFormat:image.PixelMapFormat.RGBA_8888}this.pixelMapawaitimageResource.createPixelMap(opts);}constdirgetContext(this).filesDir;console.info(save path: dir);cPixelMapToMat.accessToMat(this.pixelMap,dir);}build(){Row(){Column(){Image(this.pixelMap).width(200).height(200)Button(ArrayBufferToMat).onClick((){this.arrayBufferToMat();})Button(AccessToMat).onClick((){this.accessToMat();})}.width(100%)}.height(100%)}}3. 将arraybuffer转换成cv::mat#includenapi/native_api.h#includemultimedia/image_framework/image_mdk.h#includemultimedia/image_framework/image_mdk_common.h#includemultimedia/image_framework/image_pixel_map_mdk.h#includemultimedia/image_framework/image_pixel_map_napi.h#includehilog/log.h#includeopencv2/opencv.hpp#includebits/alltypes.hstaticnapi_valueArrayBufferToMat(napi_env env,napi_callback_info info){size_t argc3;napi_value args[3]{nullptr};napi_get_cb_info(env,info,argc,args,nullptr,nullptr);napi_value error;napi_create_int32(env,-1,error);// Initialize PixelMap object dataNativePixelMap*nativeOH_PixelMap_InitNativePixelMap(env,args[0]);if(nativenullptr){returnerror;}// Obtaining Image InformationstructOhosPixelMapInfospixelMapInfos;if(OH_PixelMap_GetImageInfo(native,pixelMapInfos)!IMAGE_RESULT_SUCCESS){OH_LOG_Print(LOG_APP,LOG_ERROR,0xFF00,Test,Pure : -1);returnerror;}// Obtains the buffernapi_value bufferargs[1];napi_valuetype valueType;napi_typeof(env,buffer,valueType);if(valueTypenapi_object){boolisArrayBufferfalse;napi_is_arraybuffer(env,buffer,isArrayBuffer);if(!isArrayBuffer){napi_throw_error(env,EINVAL,Error);}}void*datanullptr;size_t byteLength0;napi_get_arraybuffer_info(env,buffer,data,byteLength);int32_t*saveBuffer(int32_t*)(data);// Convert to Matcv::MatoriginMat(pixelMapInfos.height,pixelMapInfos.width,CV_8UC4,saveBuffer);if(!originMat.data){OH_LOG_Print(LOG_APP,LOG_ERROR,0xFF00,Read Image,Pure : -1);returnerror;}// openCV defaults to BGRA or BGR. If the pixelmap is not created in one of these formats, a format conversion is requiredcv::Mat saveMat;cv::cvtColor(originMat,saveMat,cv::COLOR_BGRA2RGBA);charpathArray[1024];size_t length;napi_get_value_string_utf8(env,args[2],pathArray,1024,length);std::stringpath(pathArray);path/buffer.jpg;if(!cv::imwrite(path,saveMat)){OH_LOG_Print(LOG_APP,LOG_ERROR,0xFF00,Write Image,Pure : -1);returnerror;}napi_value res;napi_create_int32(env,1,res);returnres;}4. 使用OH_PixelMap_AccessPixels获取PixelMap的内存地址将这个内存地址中的数据转换为cv::mat的staticnapi_valueAccessToMat(napi_env env,napi_callback_info info){size_t argc2;napi_value args[2]{nullptr};napi_get_cb_info(env,info,argc,args,nullptr,nullptr);napi_value error;napi_create_int32(env,-1,error);NativePixelMap*nativeOH_PixelMap_InitNativePixelMap(env,args[0]);if(nativenullptr){returnerror;}structOhosPixelMapInfospixelMapInfos;if(OH_PixelMap_GetImageInfo(native,pixelMapInfos)!IMAGE_RESULT_SUCCESS){OH_LOG_Print(LOG_APP,LOG_ERROR,0xFF00,Test,Pure : -1);returnerror;}void*pixel;// Obtain the memory address of the NativePixelMap object and lock the memoryOH_PixelMap_AccessPixels(native,pixel);// Convert to Mat, pay attention to alignment, so rowSize needs to be passed incv::MatoriginMat(pixelMapInfos.height,pixelMapInfos.width,CV_8UC4,pixel,pixelMapInfos.rowSize);if(!originMat.data){OH_LOG_Print(LOG_APP,LOG_ERROR,0xFF00,Read Image,Pure : -1);returnerror;}// openCV defaults to BGRA or BGR. If the pixelmap is not created in one of these formats, a format conversion is requiredcv::Mat saveMat;cv::cvtColor(originMat,saveMat,cv::COLOR_BGRA2RGBA);charpathArray[1024];size_t length;napi_get_value_string_utf8(env,args[1],pathArray,1024,length);std::stringpath(pathArray);path/access.jpg;if(!cv::imwrite(path,saveMat)){OH_LOG_Print(LOG_APP,LOG_ERROR,0xFF00,Write Image,Pure : -1);returnerror;}napi_value res;napi_create_int32(env,1,res);returnres;}在HarmonyOS开发中针对图库支持硬解码的操作需要指定图像的内存空间大小。OH_PixelMap_AccessPixels() 获取图片的内存地址并锁定该内存。实际图像的大小需要按 lineStride 对齐。因此在构造成 mat 时需指定 lineStride 对齐。lineStride即 rowSize。可以使用 OH_GetImageInfo 获取 imageInfo其中包含 width、height 和 rowSize 等信息。