Android人脸识别Demo竖屏YUV方向调整和图片保存

快来打我* 2022-06-03 04:35 86阅读 0赞

本博客包含三个常用方法，用于盛开Android版人脸识别Demo中竖屏使用时送入yuv数据，但一直无法识别的情况。  
1.首先可以尝试顺时针旋转90°或270°，然后送入识别SDK。  
2.旋转方向后依然无法识别时，可以尝试saveImg( )，保存本地检查图片是否符合要求。

![这里写图片描述][SouthEast]

/** * 视频顺时针旋转90 * 该方法仅仅在竖屏时候使用 * */
        public static byte[] rotateYUV420Degree90(byte[] data, int imageWidth,
                                            int imageHeight) {
    
            byte[] yuv = new byte[imageWidth * imageHeight * 3 / 2];
            int i = 0;
            for (int x = 0; x < imageWidth; x++) {
                for (int y = imageHeight - 1; y >= 0; y--) {
                    yuv[i] = data[y * imageWidth + x];
                    i++;
                }
            }
            i = imageWidth * imageHeight * 3 / 2 - 1;
            for (int x = imageWidth - 1; x > 0; x = x - 2) {
                for (int y = 0; y < imageHeight / 2; y++) {
                    yuv[i] = data[(imageWidth * imageHeight) + (y * imageWidth) + x];
                    i--;
                    yuv[i] = data[(imageWidth * imageHeight) + (y * imageWidth)
                            + (x - 1)];
                    i--;
                }
            }
            return yuv;
        }
    
    
        public static byte[] YUV420spRotate270(byte[] src, int width, int height) {
            int count = 0;
            int uvHeight = height >> 1;
            int imgSize = width * height;
            byte[] des = new byte[imgSize * 3 >> 1];
            //copy y
            for (int j = width - 1; j >= 0; j--) {
                for (int i = 0; i < height; i++) {
                    des[count++] = src[width * i + j];
                }
            }
            //u,v
            for (int j = width - 1; j > 0; j -= 2) {
                for (int i = 0; i < uvHeight; i++) {
                    des[count++] = src[imgSize + width * i + j - 1];
                    des[count++] = src[imgSize + width * i + j];
                }
            }
            return des;
        }
    
     private int i = 1;
        private String path = Environment.getExternalStorageDirectory().getAbsolutePath() + "/0Face/";
        private Calendar now = new GregorianCalendar();
        private SimpleDateFormat simpleDate = new SimpleDateFormat("yyyyMMddHHmmss", Locale.getDefault());
        private String fileName = simpleDate.format(now.getTime());
    
    
        /** * @param data yuv图像数据 * @param width * @param height */
        public void saveImg(byte[] data, int width, int height) {
            File dir = new File(path);
            if (!dir.exists()) dir.mkdirs();
            File f = new File(path + (fileName + "-" + i++) + ".jpg");
            FileOutputStream fOut = null;
            try {
                //yuv转成bitmap
                YuvImage image = new YuvImage(data, ImageFormat.NV21, width, height, null);
                ByteArrayOutputStream stream = new ByteArrayOutputStream();
                image.compressToJpeg(new Rect(0, 0, width, height), 80, stream);
                Bitmap bmp = BitmapFactory.decodeByteArray(stream.toByteArray(), 0, stream.size());
               //bitmap保存至本地
                fOut = new FileOutputStream(f);
                bmp.compress(Bitmap.CompressFormat.JPEG, 100, fOut);
                fOut.flush();
                fOut.close();
                bmp.recycle();
                stream.close();
            } catch (Exception ex) {
                Log.e("Sys", "Error:" + ex.getMessage());
            }
        }

[SouthEast]: /images/20220603/e2dc4a80787348b48164e5dd6620fac6.png