如何在 Android 上将原始相机数据转换为位图

Question

I obtain raw camera data rawData of type byte[] , format RGBA, size 640x480, 4 bytes per pixel, from a library function. And I need to convert it to a Bitmap and display in an ImageView on the screen.

What I do is the following:

byte[] JPEGData = convertToJpeg(rawData, 640, 480, 80);
Bitmap bitmap = BitmapFactory.decodeByteArray(JPEGData , 0, JPEGData .length);    
imageView.setImageBitmap(bitmap);

where convertToJpeg() function is:

    public static byte[] convertToJpeg(byte[] buffer, int w, int h, int quality) {
        YuvImage yuv_image = new YuvImage(buffer, ImageFormat.NV21, w, h, null);

        Rect rect = new Rect(0, 0, w, h);
        ByteArrayOutputStream output_stream = new ByteArrayOutputStream();
        yuv_image.compressToJpeg(rect, quality, output_stream);

        Bitmap sourceBmp = BitmapFactory.decodeByteArray(output_stream.toByteArray(), 0, output_stream.size());
        Bitmap destBmp = Bitmap.createScaledBitmap(sourceBmp, (int) (w * 0.75), (int) (h * 0.75), true);

        ByteArrayOutputStream pictureStream = new ByteArrayOutputStream();
        destBmp.compress(CompressFormat.JPEG, quality, pictureStream);
        byte[] pictureByteArray = pictureStream.toByteArray();

        return pictureByteArray;
    }

After decodeByteArray() call I have bitmap.getConfig() == ARGB_8888 .

However, what I see on the screen is some chaotic picture, with some blurry green shapes of what's been in the original picture.

What's wrong with it?

Answer 1

The solution has turned out to be simple. And no need to convert to JPEG.

Bitmap bm = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
bm.copyPixelsFromBuffer(ByteBuffer.wrap(rawData));

Answer 2

ByteBuffer().rewind 将缓冲区位置重置为 0，而不是解决了“缓冲区不足以容纳像素”