以人像模式从相机拍摄的加载到画布上的照片为横向

Question

If I take a photo with my camera in android in portrait mode, and then load it as a bitmap and draw it to a canvas it appears rotated counter clockwise 90 degrees and in landscape orientation. I use BitmapFactory.decodeFile(imagePath); to load the image. Does anyone know why this would happen?

Answer 1

Please see the answer at Android: Photos force captured in Landscape mode .

The bottom line is, capture preserves the hardware camera orientation, which is landscape in most telephones. You have few ways to find the actual orientation of the device vs. the horizon when the picture was taken, eg the EXIF header of the JPEG file. Bitmap method that decodes such file does not respect the EXIF info, even if it is present. But you can choose one of the ways to apply rotation to the bitmap after it is loaded.

An alternative is to apply rotation to the captured JPEG file, as described in Lossless JPEG Rotate (90/180/270 degrees) in Java? . There is even an app on the PlayStore to do it: https://play.google.com/store/apps/details?id=com.lunohod.jpegtool .