Image processing 在android中将Argb8888图像转换为YUV420 sp会产生绿色图像
您好，我正在尝试将Argb8888图像转换为android中的YUV420 sp，我得到了一个完全绿色的压缩图像。如果我使用正确的方法，请在代码方面帮助我。 代码如下所示Image processing 在android中将Argb8888图像转换为YUV420 sp会产生绿色图像,image-processing,Image Processing,您好，我正在尝试将Argb8888图像转换为android中的YUV420 sp，我得到了一个完全绿色的压缩图像。如果我使用正确的方法，请在代码方面帮助我。 代码如下所示 Image(Context context) { // This Constructor is used to initialize height and width of screen screenHeight = 800;//m1.he
Image(Context context) {
// This Constructor is used to initialize height and width of screen
screenHeight = 800;//m1.heightPixels;
screenWidth = 480;//m1.widthPixels;
bufferSize = 4 * screenHeight * screenWidth;
buffer = new byte[bufferSize];
newarrs =new byte[bufferSize];
log("constructor width:- " + screenWidth + " height:- " + screenHeight);
}
public void capture() {
// Take the Data from frame buffer and store in buffer
log("capture Screen");
BufferedInputStream bis = null;
try {
// log("in try");
bis = new BufferedInputStream(new FileInputStream("/data/fb0.raw"));
readSize = bis.read(buffer, 0, bufferSize);
bis.close();
}
catch (Exception e) {
// log("in catch");
e.printStackTrace();
}
encodeYUV420(buffer);
byte[] arr = resize1(buffer);
FileOutputStream fos;
try {
File f = Files.getImageFile();
fos = new FileOutputStream(f);
fos.write(arr);
fos.close();
} catch (Exception e) {
}
private byte[] resize1(byte[] buffer) {
final int RATIO = 4;
byte[][][] newBuff = new byte[screenWidth][screenHeight][4];
int pos1 = 0;
for (int i = 0; i < screenWidth; i++) {
for (int j = 0; j < screenHeight; j++) {
newBuff[i][j][0] = buffer[pos1++];
newBuff[i][j][1] = buffer[pos1++];
newBuff[i][j][2] = buffer[pos1++];
newBuff[i][j][3] = buffer[pos1++];
}
}
byte[] buffer1 = new byte[buffer.length*3 / (RATIO * RATIO)];
int pos2 = 0;
int i = 0, j = 0;
for (i = 0; i < screenWidth; i++) {
for (j = 0; j < screenHeight; j++) {
try {
if (i % RATIO == 0 && j % RATIO == 0) {
buffer1[pos2++] = newBuff[i][j][0];
buffer1[pos2++] = newBuff[i][j][1];
buffer1[pos2++] = newBuff[i][j][2];
buffer1[pos2++] = newBuff[i][j][3];
}
} catch (Exception e) {
log(" i " + i + " j " + j);
}
}
}
log(" valuesof i " + i + " j " + j);
if (pos2 == buffer.length / (RATIO * RATIO))
log("S size:- " + pos2);
else
log("F size:- " + pos2);
return buffer1;
}
private byte[] encodeYUV420(byte[] argb) {
byte[] yuv420sp = new byte[(screenHeight * screenWidth * 3) / 2];
final int frameSize = screenWidth * screenHeight;
int yIndex = 0;
int uIndex = frameSize;
int vIndex = frameSize + (frameSize / 4);
int R, G, B;
int Y, U, V;
int index = 0;
for (int j = 0; j < screenHeight; j++) {
for (int i = 0; i < screenWidth; i++) {
int pp = (j * screenWidth + i) * 4;
//a = (argb[index] & 0xff000000) >> 24; // a is not used obviously
R = (argb[index] & 0xff0000) >> 16;
G = (argb[index] & 0xff00) >> 8;
B = (argb[index] & 0xff) >> 0;
Y = ((66 * R + 129 * G + 25 * B + 128) >> 8) + 16;
U = ((-38 * R - 74 * G + 112 * B + 128) >> 8) + 128;
V = ((112 * R - 94 * G - 18 * B + 128) >> 8) + 128;
yuv420sp[yIndex++] = (byte) ((Y < 0) ? 0 : ((Y > 255) ? 255 : Y));
if (j % 2 == 0 && i % 2 == 0) {
yuv420sp[uIndex++] = (byte) ((U<0) ? 0 : ((U > 255) ? 255 : U));
yuv420sp[vIndex++] = (byte) ((V<0) ? 0 : ((V > 255) ? 255 : V));
}
}
return yuv420sp;
}
Image(Context context) {
// This Constructor is used to initialize height and width of screen
screenHeight = 800;//m1.heightPixels;
screenWidth = 480;//m1.widthPixels;
bufferSize = 4 * screenHeight * screenWidth;
buffer = new byte[bufferSize];
newarrs =new byte[bufferSize];
log("constructor width:- " + screenWidth + " height:- " + screenHeight);
}
public void capture() {
// Take the Data from frame buffer and store in buffer
log("capture Screen");
BufferedInputStream bis = null;
try {
// log("in try");
bis = new BufferedInputStream(new FileInputStream("/data/fb0.raw"));
readSize = bis.read(buffer, 0, bufferSize);
bis.close();
}
catch (Exception e) {
// log("in catch");
e.printStackTrace();
}
encodeYUV420(buffer);
byte[] arr = resize1(buffer);
FileOutputStream fos;
try {
File f = Files.getImageFile();
fos = new FileOutputStream(f);
fos.write(arr);
fos.close();
} catch (Exception e) {
}
private byte[] resize1(byte[] buffer) {
final int RATIO = 4;
byte[][][] newBuff = new byte[screenWidth][screenHeight][4];
int pos1 = 0;
for (int i = 0; i < screenWidth; i++) {
for (int j = 0; j < screenHeight; j++) {
newBuff[i][j][0] = buffer[pos1++];
newBuff[i][j][1] = buffer[pos1++];
newBuff[i][j][2] = buffer[pos1++];
newBuff[i][j][3] = buffer[pos1++];
}
}
byte[] buffer1 = new byte[buffer.length*3 / (RATIO * RATIO)];
int pos2 = 0;
int i = 0, j = 0;
for (i = 0; i < screenWidth; i++) {
for (j = 0; j < screenHeight; j++) {
try {
if (i % RATIO == 0 && j % RATIO == 0) {
buffer1[pos2++] = newBuff[i][j][0];
buffer1[pos2++] = newBuff[i][j][1];
buffer1[pos2++] = newBuff[i][j][2];
buffer1[pos2++] = newBuff[i][j][3];
}
} catch (Exception e) {
log(" i " + i + " j " + j);
}
}
}
log(" valuesof i " + i + " j " + j);
if (pos2 == buffer.length / (RATIO * RATIO))
log("S size:- " + pos2);
else
log("F size:- " + pos2);
return buffer1;
}
private byte[] encodeYUV420(byte[] argb) {
byte[] yuv420sp = new byte[(screenHeight * screenWidth * 3) / 2];
final int frameSize = screenWidth * screenHeight;
int yIndex = 0;
int uvIndex=frameSize;
int a, R, G, B, Y, U, V;
int index = 0;
for (int j = 0; j < height; j++) {
for (int i = 0; i < width; i++) {
int pp = (j * width + i) * 4;
R = argb[pp+ 0];
G = argb[pp + 1];
B = argb[pp + 2];
a = argb[pp + 3];
Y = ( ( 66 * R + 129 * G + 25 * B + 128) >> 8) + 16;
U = ( ( -38 * R - 74 * G + 112 * B + 128) >> 8) + 128;
V = ( ( 112 * R - 94 * G - 18 * B + 128) >> 8) + 128;
yuv420sp[yIndex++] = (byte) ((Y < 0) ? 0 : ((Y > 255) ? 255 : Y));
if (j % 2 == 0 && i % 2 == 0) {
yuv420sp[uvIndex++] = (byte)((U<0) ? 0 : ((U > 255) ? 255 : U));
yuv420sp[uvIndex++] = (byte)((V<0) ? 0 : ((V > 255) ? 255 : V));
}
}
return yuv420sp;
}
您没有正确存储YUV数据。根据本发明，YUV420SP数据存储在两个平面中，一个包含Y数据，另一个包含交错的U和V数据：
| Y_0 | Y_1 | Y_2 | Y_3 | Y_4 | ... | Y_w-2 | Y_w-1 | /* h rows */
| Y_w | Y_w+1 | Y_w+2 | ...
:
:
| U_0 | V_0 | U_2 | V_2 | U_4 | ... | U_w-2 | V_w-2 | /* h/2 rows */
| U_2w | V_2w | U_2w+2| ...
:
:
int uIndex = frameSize;
int vIndex = frameSize + (frameSize / 4);
你能缩进你的代码吗？如果我的示例代码部分出错，我可以使用任何本机api吗？或者我应该使用什么？使用一个指针存储U和V值uvIndex=frameSize；，然后，如果j%2==0 yuv420sp[uvIndex++]=i%2==0，则在该平面中交替存储U和V值？U:V；，其中，U和V是为相同的i值计算的值，即U_0、V_0、U_2、V_2等。。顺便说一下，您将丢弃由该代码计算的四分之三的U和V值。当你真正需要这些值时，只需计算它们，你就可以让它运行得更快。但它仍然是绿色的，甚至不接近任何转换。请以任何可能的方式提供帮助。上传一些输入和输出图像的示例。这可能会有帮助。如果我们想在字节数组中看到yuv格式的图像，它应该以相同的方式复制还是反转？