Update

cpp-package/inspireface/python/read_nv21.py

@@ -0,0 +1,71 @@
+import cv2
+import numpy as np
+from inspireface import ImageStream
+import inspireface as isf
+
+
+def read_nv21(file_path, width, height, rotate=0):
+    with open(file_path, 'rb') as f:
+        nv21_data = f.read()
+    
+    yuv = np.frombuffer(nv21_data, dtype=np.uint8)
+    
+    expected_size = width * height * 3 // 2
+    if len(yuv) < expected_size:
+        raise ValueError(f"NV21 data size is not enough: expected {expected_size} bytes, actual {len(yuv)} bytes")
+    
+    yuv_mat = np.zeros((height * 3 // 2, width), dtype=np.uint8)
+    yuv_mat[:] = yuv[:height * width * 3 // 2].reshape(height * 3 // 2, width)
+    
+    bgr_mat = cv2.cvtColor(yuv_mat, cv2.COLOR_YUV2BGR_NV21)
+    
+    # add reverse rotate
+    if rotate != 0:
+        # calculate reverse rotate angle
+        reverse_angle = (360 - rotate) % 360
+        
+        # select rotate method by angle
+        if reverse_angle == 90:
+            bgr_mat = cv2.rotate(bgr_mat, cv2.ROTATE_90_CLOCKWISE)
+        elif reverse_angle == 180:
+            bgr_mat = cv2.rotate(bgr_mat, cv2.ROTATE_180)
+        elif reverse_angle == 270:
+            bgr_mat = cv2.rotate(bgr_mat, cv2.ROTATE_90_COUNTERCLOCKWISE)
+        else:
+            # for non 90 degree angle, use affine transform
+            center = (bgr_mat.shape[1] // 2, bgr_mat.shape[0] // 2)
+            rotation_matrix = cv2.getRotationMatrix2D(center, reverse_angle, 1.0)
+            bgr_mat = cv2.warpAffine(bgr_mat, rotation_matrix, (bgr_mat.shape[1], bgr_mat.shape[0]))
+    
+    return bgr_mat
+
+# example usage
+if __name__ == "__main__":
+    image_width = 640
+    image_height = 480
+    nv21_file = ""
+    pre_rotate = 90
+    try:
+        # read and reverse rotate image
+        bgr_image = read_nv21(nv21_file, image_width, image_height, pre_rotate)
+        
+        cv2.imshow("origin", bgr_image)
+        
+        # show original image for comparison
+        bgr_image_original = read_nv21(nv21_file, image_width, image_height)
+        cv2.imshow("rotate ", bgr_image_original)
+        
+        cv2.waitKey(0)
+        cv2.destroyAllWindows()
+        
+    except Exception as e:
+        print(f"error: {e}")
+
+    with open(nv21_file, 'rb') as f:
+        nv21_data = f.read()
+
+    stream = ImageStream.load_from_buffer(nv21_data, image_width, image_height, isf.HF_STREAM_YUV_NV21, isf.HF_CAMERA_ROTATION_90)
+
+    stream.debug_show()
+
+