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我使用ImageFormat的相机NV21预览,当我获得NV21数据时,我尝试使用以下方法获取可显示给ImageView的字节。为什么使用100质量的位图压缩变得更小
字体:
public static byte[] n21ToBitmap(byte[] data, Camera camera) {
try {
Camera.Parameters parameters = camera.getParameters();
Camera.Size size = parameters.getPreviewSize();
YuvImage image =
new YuvImage(data, parameters.getPreviewFormat(), size.width, size.height, null);
ByteArrayOutputStream stream = new ByteArrayOutputStream();
image.compressToJpeg(new Rect(0, 0, size.width, size.height), 100, stream);
Bitmap originBitmap = BitmapFactory.decodeByteArray(stream.toByteArray(), 0, stream.size());
stream.close();
Matrix matrix = new Matrix();
matrix.postRotate(270);
Bitmap rotateBitmap =
Bitmap.createBitmap(originBitmap, 0, 0, originBitmap.getWidth(), originBitmap.getHeight(),
matrix, true);
Bitmap temp = rotateBitmap.copy(rotateBitmap.getConfig(), true);
Log.e("TAG", "n21ToBitmap(ImageUtils.java:"
+ Thread.currentThread().getStackTrace()[2].getLineNumber()
+ ")"
+ "temp:"
+ temp.getByteCount());
stream = new ByteArrayOutputStream();
temp.compress(Bitmap.CompressFormat.JPEG, 100, stream);
byte[] bytes = stream.toByteArray();
Log.e("TAG", "n21ToBitmap(ImageUtils.java:"
+ Thread.currentThread().getStackTrace()[2].getLineNumber()
+ ")"
+ "bytes:"
+ bytes.length);
return bytes;
} catch (Exception ex) {
Log.e(TAG, "Error:" + ex.getMessage());
}
return null;
}
和日志:
n21ToBitmap(ImageUtils.java:103)temp: 2073600
n21ToBitmap(ImageUtils.java:112)bytes:311627
那么,为什么字节长度成为smallar?
这是JPG格式的压缩器:) – Vyacheslav
但是为什么当你使用系统相机拍照时,你会得到一个大的图像?这也是JPG图片。 – ChengTao