Bugfix/image buffer release

src/python/k4a/setup.py

@@ -2,7 +2,7 @@
 
 setup(
     name='k4a',
-    version='0.0.2',
+    version='0.0.3',
     author='Jonathan Santos',
     author_email='[email protected]',
     description='Python interface to Azure Kinect API.',

src/python/k4a/src/k4a/_bindings/image.py

@@ -13,11 +13,11 @@
 import numpy as _np
 import copy as _copy
 
-from .k4atypes import _ImageHandle, EStatus, EImageFormat
+from .k4atypes import _ImageHandle, EStatus, EImageFormat, _memory_destroy_cb
 
 from .k4a import k4a_image_create, k4a_image_create_from_buffer, \
     k4a_image_release, k4a_image_get_buffer, \
-    k4a_image_reference, k4a_image_release, k4a_image_get_format, \
+    k4a_image_reference, k4a_image_get_format, \
     k4a_image_get_size, k4a_image_get_width_pixels, \
     k4a_image_get_height_pixels, k4a_image_get_stride_bytes, \
     k4a_image_get_device_timestamp_usec, k4a_image_set_device_timestamp_usec, \
@@ -280,6 +280,19 @@ def _create_from_existing_image_handle(
 
         return image
 
+    @staticmethod
+    @_memory_destroy_cb
+    def _buffer_destroy_callback(buffer: _ctypes.c_void_p, context: _ctypes.c_void_p):
+        """
+        Skip decrementing the reference count on the array when the buffer is released
+        :param buffer:  The image buffer
+        :param context: The array buffer object
+        :return: None
+        """
+        # This function will probably not be called, but the buffer shouldn't be released
+        # since it is referenced by a numpy array
+        pass
+
     @staticmethod
     def create(
         image_format:EImageFormat,
@@ -400,47 +413,49 @@ def create_from_ndarray(
         '''
         image = None
 
-        assert(isinstance(arr, _nd.ndarray)), "arr must be a numpy ndarray object."
-        assert(isinstance(image_format, EImageFormat)), "image_format parameter must be an EImageFormat."
+        assert (isinstance(arr, _np.ndarray)), "arr must be a numpy ndarray object."
+        assert (isinstance(image_format, EImageFormat)), "image_format parameter must be an EImageFormat."
 
         # Get buffer pointer and sizes of the numpy ndarray.
-        buffer_ptr = ctypes.cast(
-            _ctypes.addressof(np.ctypeslib.as_ctypes(arr)), 
-            _ctypes.POINTER(_ctypes.c_uint8))
-
-        width_pixels = _ctypes.c_int(width_pixels_custom)
-        height_pixels = _ctypes.c_int(height_pixels_custom)
-        stride_bytes = _ctypes.c_int(stride_bytes_custom)
-        size_bytes = _ctypes.c_size_t(size_bytes_custom)
-
-        # Use the ndarray sizes if the custom size info is not passed in.
-        if width_pixels == 0:
-            width_pixels = _ctypes.c_int(arr.shape[0])
-
-        if height_pixels == 0:
-            height_pixels = _ctypes.c_int(arr.shape[1])
-
-        if size_bytes == 0:
-            size_bytes = _ctypes.c_size_t(arr.itemsize * arr.size)
-
-        if len(arr.shape) > 2 and stride_bytes == 0:
-            stride_bytes = _ctypes.c_int(arr.shape[2])
-
-        # Create image from the numpy buffer.
-        image_handle = _ImageHandle()
-        status = k4a_image_create_from_buffer(
-            image_format,
-            width_pixels,
-            height_pixels,
-            stride_bytes,
-            buffer_ptr,
-            size_bytes,
-            None,
-            None,
-            _ctypes.byref(image_handle))
-
-        if status == EStatus.SUCCEEDED:
-            image = Image._create_from_existing_image_handle(image_handle)
+        buffer_ptr = _ctypes.cast(_np.ctypeslib.as_ctypes(arr), _ctypes.POINTER(_ctypes.c_uint8))
+        array_obj = _ctypes.py_object(arr)
+        # Hold onto the buffer memory by incrementing the reference count on the array object
+        _ctypes.pythonapi.Py_IncRef(array_obj)
+
+        try:
+            # Use the ndarray sizes if the custom size info is not passed in.
+            width_pixels = _ctypes.c_int(arr.shape[1]) \
+                if width_pixels_custom == 0 else _ctypes.c_int(width_pixels_custom)
+            height_pixels = _ctypes.c_int(arr.shape[0]) \
+                if height_pixels_custom == 0 else _ctypes.c_int(height_pixels_custom)
+            stride_bytes = _ctypes.c_int(arr.strides[0]) \
+                if stride_bytes_custom == 0 else _ctypes.c_int(stride_bytes_custom)
+            size_bytes = _ctypes.c_size_t(arr.itemsize * arr.size) \
+                if size_bytes_custom == 0 else _ctypes.c_size_t(size_bytes_custom)
+
+            # Create image from the numpy buffer.
+            image_handle = _ImageHandle()
+            status = k4a_image_create_from_buffer(
+                image_format,
+                width_pixels,
+                height_pixels,
+                stride_bytes,
+                buffer_ptr,
+                size_bytes,
+                Image._buffer_destroy_callback,
+                _ctypes.cast(_ctypes.pointer(array_obj), _ctypes.c_void_p),
+                _ctypes.byref(image_handle))
+
+            if status == EStatus.SUCCEEDED:
+                image = Image._create_from_existing_image_handle(image_handle)
+                # Delete the array object created indirectly by _create_from_existing_image_handle
+                # without deleting the data
+                del image.data
+                # Use the given array object instead (this won't create a new reference)
+                image._data = arr
+        except _ctypes.ArgumentError as details:
+            _ctypes.pythonapi.Py_DecRef(array_obj)
+            raise _ctypes.ArgumentError(details)
 
         return image
 
@@ -514,7 +529,7 @@ def __deepcopy__(self, memo):
     def __enter__(self):
         return self
 
-    def __exit__(self):
+    def __exit__(self, *exception_details):
         del self
 
     def __str__(self):
@@ -549,7 +564,7 @@ def _image_handle(self):
 
     @_image_handle.deleter
     def _image_handle(self):
-        
+
         # Release the image before deleting.
         if isinstance(self._data, _np.ndarray):
             if not self._data.flags.owndata:

src/python/k4a/src/k4a/_bindings/k4a.py

@@ -23,9 +23,30 @@
     _TransformationHandle, _Calibration, _Float2, _Float3, \
     _memory_allocate_cb, _memory_destroy_cb
 
-
-__all__ = []
-
+__all__ = ['k4a_image_create', 'k4a_image_create_from_buffer', 'k4a_set_debug_message_handler',
+           'k4a_image_release', 'k4a_image_get_buffer',
+           'k4a_image_reference', 'k4a_image_get_format',
+           'k4a_image_get_size', 'k4a_image_get_width_pixels',
+           'k4a_image_get_height_pixels', 'k4a_image_get_stride_bytes',
+           'k4a_image_get_device_timestamp_usec', 'k4a_image_set_device_timestamp_usec',
+           'k4a_image_get_system_timestamp_nsec', 'k4a_image_set_system_timestamp_nsec',
+           'k4a_image_get_exposure_usec', 'k4a_image_set_exposure_usec',
+           'k4a_image_get_white_balance', 'k4a_image_set_white_balance',
+           'k4a_image_get_iso_speed', 'k4a_image_set_iso_speed', 'k4a_calibration_get_from_raw',
+           'k4a_capture_create', 'k4a_capture_release', 'k4a_capture_reference',
+           'k4a_capture_get_color_image', 'k4a_capture_set_color_image',
+           'k4a_capture_get_depth_image', 'k4a_capture_set_depth_image',
+           'k4a_capture_get_ir_image', 'k4a_capture_set_ir_image',
+           'k4a_capture_get_temperature_c', 'k4a_capture_set_temperature_c',
+           'k4a_device_get_installed_count', 'k4a_device_open',
+           'k4a_device_get_serialnum', 'k4a_device_get_version',
+           'k4a_device_get_color_control_capabilities', 'k4a_device_close',
+           'k4a_device_get_imu_sample', 'k4a_device_get_color_control',
+           'k4a_device_start_cameras', 'k4a_device_stop_cameras',
+           'k4a_device_start_imu', 'k4a_device_stop_imu',
+           'k4a_device_set_color_control', 'k4a_device_get_raw_calibration',
+           'k4a_device_get_sync_jack', 'k4a_device_get_capture', 'k4a_device_get_calibration'
+           ]
 
 # Load the k4a.dll.
 try:
@@ -182,9 +203,7 @@
 k4a_image_create_from_buffer.restype = EStatus
 k4a_image_create_from_buffer.argtypes=(
     _ctypes.c_int, _ctypes.c_int, _ctypes.c_int, _ctypes.c_int, _ctypes.POINTER(_ctypes.c_uint8),
-    _ctypes.c_size_t, _memory_allocate_cb, _ctypes.c_void_p, _ctypes.POINTER(_ImageHandle))
-
-
+    _ctypes.c_size_t, _memory_destroy_cb, _ctypes.c_void_p, _ctypes.POINTER(_ImageHandle))
 
 #K4A_EXPORT uint8_t *k4a_image_get_buffer(k4a_image_t image_handle);
 k4a_image_get_buffer = _k4a_lib.k4a_image_get_buffer

src/python/k4a/tests/test_create_image.py

@@ -0,0 +1,59 @@
+"""
+test_create_image.py
+
+Tests for the creating Image objects using pre-allocated arrays.
+
+"""
+
+import numpy as np
+from numpy.random import default_rng
+import unittest
+
+import k4a
+
+
+class TestImages(unittest.TestCase):
+    """Test allocation of images.
+    """
+
+    @classmethod
+    def setUpClass(cls):
+        pass
+
+    @classmethod
+    def tearDownClass(cls):
+        pass
+
+    def test_unit_create_from_ndarray(self):
+        # from inspect import currentframe, getframeinfo    # For debugging if needed
+
+        # Create an image with the default memory allocation and free
+        an_image = k4a.Image.create(k4a.EImageFormat.CUSTOM16, 640, 576, 640*2)
+        self.assertEqual(an_image.height_pixels, 576)
+        del an_image    # this will call the default image_release function
+
+        for index in range(5):
+            # We want a diverse source for the values, but also we want it to be deterministic
+            seed = 12345 + index
+            rng = default_rng(seed=seed)
+            two_channel_uint16 = rng.integers(0, high=65536, size=(576, 640), dtype=np.uint16)
+            # Uncomment these two lines to change the image buffer to show that the verification below works
+            # two_channel_uint16[0, 0] = (0x12 << 8) + 0x34
+            # two_channel_uint16[0, 1] = (0x56 << 8) + 0x78
+
+            custom_image = k4a.Image.create_from_ndarray(k4a.EImageFormat.CUSTOM16, two_channel_uint16)
+            two_channel_uint16 = rng.integers(0, high=32767, size=(576, 640), dtype=np.uint16)
+            # Ensure that the original array is no longer known locally, but the data is still available through custom_image
+            self.assertFalse(np.all(two_channel_uint16 == custom_image.data))
+            del two_channel_uint16
+
+            # Regenerate the values of the custom_image using the same seed for comparison
+            rng = default_rng(seed=seed)
+            verify_two_channel_uint16 = rng.integers(0, high=65536, size=(576, 640), dtype=np.uint16)
+
+            self.assertTrue(np.all(verify_two_channel_uint16 == custom_image.data))
+            del custom_image
+
+
+if __name__ == '__main__':
+    unittest.main()