安卓使用opencv

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android studio版本:3.6.4
gradle: 3.6.1 、5.6.4
opencv:4.5.3

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下载open cv sdk

opencv sdk 下载，我下载的是最新的4.5.3。

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创建项目

这个按正常的创建一个空Activity的项目即可

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将下载解压的opencv sdk导入到创建的项目中作为一个moudle

步骤如下:

在上面创建的项目中点击菜单: File > New > Import-Module
导入sdk文件夹
将opencv sdk中的OpenCV-android-sdk/sdk 这个“sdk目录“导入到moudle中，这里我将模块名命名为opencvtest

• 到此映入就完成了

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检测是否成功

1. 在创建的项目中引入依赖

dependencies {
    implementation project(':opencvtest')
}

2. 添加测试代码:

package com.pkyingy.mp.opencv

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.util.Log
import kotlinx.android.synthetic.main.activity_main.*
import org.opencv.android.OpenCVLoader

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        Log.e("Check", "OpenCv configured ")
        if (OpenCVLoader.initDebug()) {
            tv_tv.text = "OpenCv configured successfully"
            Log.e("Check", "OpenCv configured successfully")
        } else {
            tv_tv.text = "OpenCv configured faile"
            Log.e("Check", "OpenCv configured faile")
        }
    }
}

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可能遇到的错误:

• kotlin依赖问题

e: /Users/MacBook/Documents/projects/android/opencv/opencvtest/java/src/org/opencv/core/MatAt.kt: (6, 18): Cannot access built-in declaration 'kotlin.Int'. Ensure that you have a dependency on the Kotlin standard library

解决办法:

1. 在导入的opencvtest库的build.gradle中找到

apply plugin: 'com.android.library'
apply plugin: 'kotlin-android'

2. 添加 apply plugin: 'kotlin-android-extensions',如下所示

apply plugin: 'com.android.library'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-android-extensions'

• NDK环境问题

A problem occurred configuring project ':opencv4_5_3'.
> NDK not configured. Download it with SDK manager. Preferred NDK version is '20.0.5594570'. Log: /Users/MacBook/Documents/projects/android/pk-android-libs/opencv4_5_3/.cxx/ndk_locator_record.json

解决办法: 在项目根目录的local.properties文件中添加电脑上的dnk路径

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其他网址

• opencv api
• opencv 安卓论坛(需要梯子)