我试图将图像从YUV_420_888转换为rgb,并且在输出图像时遇到了一些麻烦。在ImageReader中,我以YUV_420_888格式(使用相机2 api获取此图像预览)获取图像。camera2 api将yuv420转换为rgb绿色
imageReader = ImageReader.newInstance(1920,1080,ImageFormat.YUV_420_888,10);
在为YuvImage类写作Android SDK中,该YuvImage只使用NV21,YUY2。
我们可以看到差异N21和YUV420之间并不大,我尝试数据转换为N21
在onImageAvailable我分别得到每架飞机,并把它们放在正确的地方(如图)
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
ByteBuffer bufferY = image.getPlanes()[0].getBuffer();
byte[] data0 = new byte[bufferY.remaining()];
bufferY.get(data0);
ByteBuffer bufferU = image.getPlanes()[1].getBuffer();
byte[] data1 = new byte[bufferU.remaining()];
bufferU.get(data1);
ByteBuffer bufferV = image.getPlanes()[2].getBuffer();
byte[] data2 = new byte[bufferV.remaining()];
bufferV.get(data2);
...
outputStream.write(data0);
for (int i=0;i<bufferV.remaining();i++) {
outputStream.write(data1[i]);
outputStream.write(data2[i]);
}
后创建YuvImage,转换为位图,查看和保存
final YuvImage yuvImage = new YuvImage(outputStream.toByteArray(), ImageFormat.NV21, 1920,1080, null);
ByteArrayOutputStream outBitmap = new ByteArrayOutputStream();
yuvImage.compressToJpeg(new Rect(0, 0,1920, 1080), 95, outBitmap);
byte[] imageBytes = outBitmap.toByteArray();
final Bitmap imageBitmap = BitmapFactory.decodeByteArray(imageBytes, 0, imageBytes.length);
mImageView.setImageBitmap(imageBitmap);
...
imageBitmap.compress(Bitmap.CompressFormat.JPEG, 95, out);
我错过了什么?
小点:为NV21图其实是错误的,并描述了NV12编码。除了交换U和V之外,NV21是相同的,即VUVUVUVUV而不是UVUVUVUVUV。 – samgak