基于web的android图像处理示例(Win7+Apache+PHP+Matlab+Android)
本文将介绍C/S模式的图像处理系统。C/S的框架已经在[1]中作了简单的介绍。[2]中介绍了如何搭建基于android和WAMP5的B/S模式的本机测试平台。本系统是在[4]中介绍的基础上开发的,有关图像显示和本地图像处理的框架可以参看[4];
@author:郑海波 zhb931706659@126.com
转载请声明:http://blog.csdn.net/nuptboyzhb/article/details/7945249
实验结果展示:(图像的DCT变换)
实验平台:
服务器:Windows 7+Apache+MySQL+PHP
客户端:Android
开发工具:Eclipse+ADT+AVD
我们先看客户端(Client)的android开发
1.图像处理框架:
本次试验的图像处理框架我们依然使用[4]的实验平台。该实验平台已经实现了图像的打开,保存,摄像,截屏,显示和简单的图像处理算法等功能。
我们本次试验,需要用到该框架的图像打开,显示,保存等基本功能。
2.客户端的核心
在客户端,C/S模式的核心就是如何将本机数据发送到服务器,并从服务器中下载处理完后的数据。由于连接服务器,发送,接收等需要较长时间,因此
我们将其过程封装到一个AsyncTask派生的类中,代码如下:
[java code]
public class ServerTask extends AsyncTask<String, Integer , Void>{public byte[] dataToServer;//Task stateprivate final int UPLOADING_PHOTO_STATE = 0;private final int SERVER_PROC_STATE = 1;private ProgressDialog dialog;//upload photo to serverHttpURLConnection uploadPhoto(FileInputStream fileInputStream){//final String serverFileName = "test"+ (int) Math.round(Math.random()*1000) + ".jpg";final String serverFileName = "test.jpg";final String lineEnd = "\r\n";final String twoHyphens = "--";final String boundary = "*****";Log.e("msg","begin HttpURLConnection......");try{URL url = new URL(SERVERURL);// Open a HTTP connection to the URLfinal HttpURLConnection conn = (HttpURLConnection)url.openConnection();// Allow Inputsconn.setDoInput(true);// Allow Outputsconn.setDoOutput(true);// Don't use a cached copy.conn.setUseCaches(false);// Use a post method.conn.setRequestMethod("POST");conn.setRequestProperty("Connection", "Keep-Alive");conn.setRequestProperty("Content-Type", "multipart/form-data;boundary="+boundary);DataOutputStream dos = new DataOutputStream( conn.getOutputStream() );dos.writeBytes(twoHyphens + boundary + lineEnd);dos.writeBytes("Content-Disposition: form-data; name=\"uploadedfile\";filename=\"" + serverFileName +"\"" + lineEnd);dos.writeBytes(lineEnd);// create a buffer of maximum sizeint bytesAvailable = fileInputStream.available();int maxBufferSize = 1024;int bufferSize = Math.min(bytesAvailable, maxBufferSize);byte[] buffer = new byte[bufferSize];// read file and write it into form...int bytesRead = fileInputStream.read(buffer, 0, bufferSize);while (bytesRead > 0){dos.write(buffer, 0, bufferSize);bytesAvailable = fileInputStream.available();bufferSize = Math.min(bytesAvailable, maxBufferSize);bytesRead = fileInputStream.read(buffer, 0, bufferSize);}// send multipart form data after file data...dos.writeBytes(lineEnd);dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd);publishProgress(SERVER_PROC_STATE);// close streamsfileInputStream.close();dos.flush();Log.e("msg","upload finished!");return conn;}catch (MalformedURLException ex){Log.e(TAG, "error: " + ex.getMessage(), ex);return null;}catch (IOException ioe){Log.e(TAG, "error: " + ioe.getMessage(), ioe);return null;}} //get image result from server and display it in result viewvoid getResultImage(HttpURLConnection conn){// retrieve the response from serverInputStream is;try {is = conn.getInputStream();//get result image from server resultForWebImage = BitmapFactory.decodeStream(is); is.close(); IsShowingResult = true; Log.d("msg","download finished!");} catch (IOException e) {Log.e(TAG,"getResultImage:"+e.toString());e.printStackTrace();}}//Main code for processing image algorithm on the servervoid processImage(String inputImageFilePath){publishProgress(UPLOADING_PHOTO_STATE);File inputFile = new File(inputImageFilePath);try {//create file stream for captured image fileFileInputStream fileInputStream = new FileInputStream(inputFile); //upload photo final HttpURLConnection conn = uploadPhoto(fileInputStream); //get processed photo from server if (conn != null){ getResultImage(conn); //String download="http://10.10.145.154/EE368_Android_Tutorial3_Server/computeSIFTOnSCIEN.php"; }fileInputStream.close();} catch (FileNotFoundException ex){ Log.e(TAG, "processImage"+ex.toString()); } catch (IOException ex){ Log.e(TAG, "processImage"+ex.toString()); }} public ServerTask() { dialog = new ProgressDialog(SystemMain.this); } protected void onPreExecute() { this.dialog.setMessage("Photo captured"); this.dialog.show(); }@Overrideprotected Void doInBackground(String... params) {//background operation String uploadFilePath = params[0];processImage(uploadFilePath);//release camera when previous image is processedmCameraReadyFlag = true; return null;}//progress update, display dialogs@Override protected void onProgressUpdate(Integer... progress) { if(progress[0] == UPLOADING_PHOTO_STATE){ dialog.setMessage("Uploading"); dialog.show(); } else if (progress[0] == SERVER_PROC_STATE){ if (dialog.isShowing()) { dialog.dismiss(); } dialog.setMessage("Processing"); dialog.show(); } } @Override protected void onPostExecute(Void param) { if (dialog.isShowing()) { dialog.dismiss(); if(IsShowingResult){ ShowImage(resultForWebImage, 2); IsShowingResult=false; } } }}
此时,我们只需要在适当的时候,启动这个任务。当用户点击send按钮时,启动服务:
[java code]
sendBtnListener=new OnClickListener() {@Overridepublic void onClick(View v) {// TODO Auto-generated method stub if(myBitmap!=null){mClientForWeb.compressByteImage(myBitmap, 75);;ServerTask task = new ServerTask(); Log.e("msg","new ServerTask finished!"); task.execute(Environment.getExternalStorageDirectory().toString() +mClientForWeb.INPUT_IMG_FILENAME);}}};
服务器端的PHP代码和matlab代码
1.服务器端的执行流程
首先,PHP获取到客户端发送过来的数据,然后在PHP中调用matlab代码对数据进行处理。PHP将处理后的结果再发回给客户端
2.本次试验
本次试验我们将实现图像的DCT变换。也即是:对客户端发送的图像做DCT变换,然后将变换后的图像发回给客户端。
如下图:
[图]
3.matlab的执行方式
我们用命令行的方式执行matlab代码,参见[3]。在PHP中,我们只需要用exec函数调用相应的指令即可。
4.PHP代码
[php code]
<?php#-------------------------------------------# EE368 Digital Image Processing# Android Tutorial #3: Server-Client Interaction Example for Image Processing# Author: Derek Pang (dcypang@stanford.edu), David Chen (dmchen@stanford.edu)#------------------------------------------#function for streaming file to clientfunction streamFile($location, $filename, $mimeType='application/octet-stream'){ if(!file_exists($location)) { header ("HTTP/1.0 404 Not Found"); return; } $size=filesize($location); $time=date('r',filemtime($location)); #html response header header('Content-Description: File Transfer'); header("Content-Type: $mimeType"); header('Cache-Control: public, must-revalidate, max-age=0'); header('Pragma: no-cache'); header('Accept-Ranges: bytes'); header('Content-Length:'.($size)); header("Content-Disposition: inline; filename=$filename"); header("Content-Transfer-Encoding: binary\n"); header("Last-Modified: $time"); header('Connection: close'); ob_clean(); flush(); readfile($location);}#**********************************************************#Main script#**********************************************************#<1>set target path for storing photo uploads on the server$photo_upload_path = "./upload/";$photo_upload_path = $photo_upload_path. basename( $_FILES['uploadedfile']['name']); #<2>set target path for storing result on the server$processed_photo_output_path = "./output/processed_";$processed_photo_output_path = $processed_photo_output_path. basename( $_FILES['uploadedfile']['name']); $downloadFileName = 'processed_' . basename( $_FILES['uploadedfile']['name']); #<3>modify maximum allowable file size to 10MB and timeout to 300sini_set('upload_max_filesize', '10M'); ini_set('post_max_size', '10M'); ini_set('max_input_time', 300); ini_set('max_execution_time', 300); #<4>Get and stored uploaded photos on the serverif(copy($_FILES['uploadedfile']['tmp_name'], $photo_upload_path)) {#<5> execute matlab image processing algorithm#example: Compute and display SIFT features using VLFeat and Matlab$command = "matlab -nojvm -nodesktop -nodisplay -r \"ImageDCT('$photo_upload_path','$processed_photo_output_path');exit\"";exec($command);#<6>stream processed photo to the clientstreamFile($processed_photo_output_path, $downloadFileName,"application/octet-stream");} else{ echo "There was an error uploading the file to $photo_upload_path !";}?>
5.Matlab代码(实现DCT变换)
[matlab code]
function ImageDCT(input_img_path, output_img_path)%-----------------------------------------% @Author: ZhengHaibo zhb931706659@126.com% Android Tutorial : Server-Client Communication%------------------------------------------% INPUT:% input_img_path - input image path% output_img_path - output image path%------------------------------------------tic;if nargin < 2 input_img_path =('./upload/test.jpg'); output_img_path =('./output/test.jpg');endif(isempty(input_img_path)) input_img_path =('./upload/test.jpg');endif(isempty(output_img_path)) output_img_path =('./output/test.jpg');end% --------------------------------% Load an image% --------------------------------InputImg = imread(input_img_path);GrayInputImg=rgb2gray(InputImg);DCT_Result=dct2(GrayInputImg)*4;imwrite(uint8(DCT_Result), output_img_path,'Quality',100);tocend
实验结果展示:
[图]
Reference:
[1]PHP学习之初:基本语法 http://blog.csdn.net/nuptboyzhb/article/details/7912483
[2]基于android和WAMP5的B/S模式的本机测试平台(android+web) http://blog.csdn.net/nuptboyzhb/article/details/7932234
[3]命令行方式执行matlab代码 :http://blog.csdn.net/nuptboyzhb/article/details/7943910
[4]Android图像处理系统1.4图像的锐化-边缘检测 :http://blog.csdn.net/nuptboyzhb/article/details/7926735
[5]斯坦福大学EE368实验室:http://www.stanford.edu/class/ee368/index.html