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我使用ImageFormat的相機NV21預覽,當我獲得NV21數據時,我嘗試使用以下方法獲取可顯示給ImageView的字節。爲什麼使用100質量的位圖壓縮變得更小
字體:
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;
}
和日誌:
n21ToBitmap(ImageUtils.java:103)temp: 2073600
n21ToBitmap(ImageUtils.java:112)bytes:311627
那麼,爲什麼字節長度成爲smallar?
這是JPG格式的壓縮器:) – Vyacheslav
但是爲什麼當你使用系統相機拍照時,你會得到一個大的圖像?這也是JPG圖片。 – ChengTao