简介
本篇是对实现图片处理功能:【加密解密】实现的记录。
实现原理
在图片上滑动的时候,会有红色画笔功能,用户可以在图片上画出想要加密的文字、图像等信息。
在初始化的时候,将被加密图片的所有R分量像素全部设置为偶数,同时复制一份未处理前的原图像到matSecret中。
在加密功能中,将画笔内容(像素值为255),和原图像matSecret所在的像素值比较,如果原图像该位置的R通道像素为偶数,则将该位置像素值+1。
简单的说,最后生成的加密图片R通道像素,在有加密信息的地方为奇数,在其他位置为偶数,另外为了方便区分导入的图片是否已经是加密图片,所以
在所有的加密图片都设置了一个头部加密信息。
在解密时候,首先检查图片头部加密信息,如果是加密图片,则将该图片R通道为奇数的像素,全部设置为红色(0,0,255);
可以参考文档:图像信息隐藏 http://blog.youkuaiyun.com/u011630458/article/details/46923507
具体代码
1、初始化
public void mySecretInit(mySecretVariable mysecretVariable){
int color, flag = 0;
mysecretVariable.mySecretpaint = new Paint();
mysecretVariable.mySecretcanvas = new Canvas();
mysecretVariable.mySecretpaint.setStyle(Style.STROKE);
mysecretVariable.mySecretpaint.setStrokeWidth(20);
mysecretVariable.mySecretpaint.setColor(Color.RED);
mysecretVariable.mySecretBitmap = getLoacalBitmap(mysecretVariable.tmpMatName).copy(Bitmap.Config.ARGB_8888, true);
mysecretVariable.mSecretDoImageView_1.setImageBitmap(mysecretVariable.mySecretBitmap);
mysecretVariable.mySecretcanvas.setBitmap(mysecretVariable.mySecretBitmap);
color = mysecretVariable.mySecretBitmap.getPixel(0, 0);
if(color != mysecretVariable.mySecretColor1)
flag = 1;
color = mysecretVariable.mySecretBitmap.getPixel(0, 1);
if(color != mysecretVariable.mySecretColor2)
flag = 2;
color = mysecretVariable.mySecretBitmap.getPixel(0, 2);
if(color != mysecretVariable.mySecretColor1)
flag = 3;
color = mysecretVariable.mySecretBitmap.getPixel(0, 3);
if(color != mysecretVariable.mySecretColor2)
flag = 4;
if(flag != 0){
mysecretVariable.mypicSecret.secretInit(mysecretVariable.mySecretDoTmpMat.getNativeObjAddr(), 0);
}
Imgcodecs.imwrite(mysecretVariable.secretMatName, mysecretVariable.mySecretDoTmpMat);
mysecretVariable.mySecretBitmap = getLoacalBitmap(mysecretVariable.secretMatName).copy(Bitmap.Config.ARGB_8888, true);
mysecretVariable.mSecretDoImageView_1.setImageBitmap(mysecretVariable.mySecretBitmap);
mysecretVariable.mySecretcanvas.setBitmap(mysecretVariable.mySecretBitmap);
}
JNIEXPORT void JNICALL Java_com_example_secret_mySecretJNI_secretInit
(JNIEnv *, jclass, jlong imageSecretInit, jint){
Mat mat = Mat(*((Mat*)imageSecretInit));
int Width = mat.rows;
int Height = mat.cols;
CvScalar s1;
IplImage src1;
int i, j;
matSecret = Mat(mat.size(), CV_8UC3);
mat.copyTo(matSecret);
src1 = mat;
for(i=0; i< Width; i++){
for(j=0; j<Height; j++){
s1 = cvGet2D(&src1, i, j);
if(((int)s1.val[2])%2 != 0){
s1.val[2] = s1.val[2] -1;
cvSet2D(&src1, i, j, s1);
}
}
}
}
首先检查一下传入的图片是否已经是被加密图片,如果不是则继续进行将图像R通道分量全部转换为偶数的处理。接着进行Android Paint和Canvas的初始化操作,以便用户可以进行输入加密信息的操作。
2、加密
public void mySecretLock(mySecretVariable mysecretVariable){
String tmp, PicPath;
mysecretVariable.mySecretBitmap.setPixel(0, 0, mysecretVariable.mySecretColor1);
mysecretVariable.mySecretBitmap.setPixel(0, 1, mysecretVariable.mySecretColor2);
mysecretVariable.mySecretBitmap.setPixel(0, 2, mysecretVariable.mySecretColor1);
mysecretVariable.mySecretBitmap.setPixel(0, 3, mysecretVariable.mySecretColor2);
saveMyBitmap(mysecretVariable.secretMatName, mysecretVariable.mySecretBitmap);
mysecretVariable.mySecretDoTmpMat = Imgcodecs.imread(mysecretVariable.secretMatName);
mysecretVariable.mypicSecret.secretLock(mysecretVariable.mySecretDoTmpMat.getNativeObjAddr(), 0);
long time =System.currentTimeMillis();
tmp = getCurrentTime(time);
PicPath = mysecretVariable.doSecretPicSavepath + tmp + ".png";
Imgcodecs.imwrite(PicPath, mysecretVariable.mySecretDoTmpMat);
Imgcodecs.imwrite(mysecretVariable.secretMatName, mysecretVariable.mySecretDoTmpMat);
mysecretVariable.mySecretBitmap = getLoacalBitmap(mysecretVariable.secretMatName).copy(Bitmap.Config.ARGB_8888, true);
mysecretVariable.mSecretDoImageView_1.setImageBitmap(mysecretVariable.mySecretBitmap);
mysecretVariable.mySecretcanvas.setBitmap(mysecretVariable.mySecretBitmap);
}
JNIEXPORT void JNICALL Java_com_example_secret_mySecretJNI_secretLock
(JNIEnv *, jclass, jlong imageSecretLock, jint){
Mat mat = Mat(*((Mat*)imageSecretLock));
int Width = mat.rows;
int Height = mat.cols;
CvScalar s1, s2;
IplImage src1, src2;
int i, j;
src1 = mat;
src2 = matSecret;
for(i=0; i< Width; i++){
for(j=0; j<Height; j++){
s1 = cvGet2D(&src1, i, j);
s2 = cvGet2D(&src2, i, j);
if(((int)s1.val[2]) == 255){
if(((int)s2.val[2])%2 == 0){
s2.val[2] = s2.val[2] + 1;
}
cvSet2D(&src1, i, j, s2);
}
}
}
}
首先给加密图片设置了加密头部,接着调用secretLock函数进行加密处理。最后出来的加密图片中,首先有一个加密头,接着该图片的R通道上加密信息位置为奇数,非加密信息位置为偶数。
3、解密
public int mySecretUnLock(mySecretVariable mysecretVariable){
int color;
color = mysecretVariable.mySecretBitmap.getPixel(0, 0);
if(color != mysecretVariable.mySecretColor1)
return -1;
color = mysecretVariable.mySecretBitmap.getPixel(0, 1);
if(color != mysecretVariable.mySecretColor2)
return -2;
color = mysecretVariable.mySecretBitmap.getPixel(0, 2);
if(color != mysecretVariable.mySecretColor1)
return -3;
color = mysecretVariable.mySecretBitmap.getPixel(0, 3);
if(color != mysecretVariable.mySecretColor2)
return -4;
mysecretVariable.mySecretDoTmpMat = Imgcodecs.imread(mysecretVariable.secretMatName);
mysecretVariable.mypicSecret.secretUnLock(mysecretVariable.mySecretDoTmpMat.getNativeObjAddr(), 0);
Imgcodecs.imwrite(mysecretVariable.secretMatName, mysecretVariable.mySecretDoTmpMat);
mysecretVariable.mySecretBitmap = getLoacalBitmap(mysecretVariable.secretMatName).copy(Bitmap.Config.ARGB_8888, true);
mysecretVariable.mSecretDoImageView_1.setImageBitmap(mysecretVariable.mySecretBitmap);
return 0;
}
JNIEXPORT void JNICALL Java_com_example_secret_mySecretJNI_secretUnLock
(JNIEnv *, jclass, jlong imageSecretUnLock, jint){
Mat mat = Mat(*((Mat*)imageSecretUnLock));
int Width = mat.rows;
int Height = mat.cols;
CvScalar s1;
IplImage src1;
int i, j;
src1 = mat;
for(i=0; i< Width; i++){
for(j=0; j<Height; j++){
s1 = cvGet2D(&src1, i, j);
if(((int)s1.val[2])%2 != 0){
s1.val[2] = 255;
s1.val[1] = 0;
s1.val[0] = 0;
}
cvSet2D(&src1, i, j, s1);
}
}
}
首先检查图像是否有加密头部,如果没有则表示该图片不是加密图片,直接返回。如果是加密图片,则通过secretUnLock函数进行解密操作。解密过程就是依次检查图片的R通道,如果为奇数,则将该位的像素设置为红色(0,0,255);
效果演示
对应的效果图片如下:
加密解密
具体演示下载:http://download.youkuaiyun.com/detail/u011630458/9261617