Convert Bit depth

Detailed Description

Converts image bit depth.

This kernel converts an image from some source bit-depth to another bit-depth as described by the table below. If the input value is unsigned the shift must be in zeros. If the input value is signed, the shift used must be an arithmetic shift. The columns in the table below are the output types and the rows are the input types. The API version on which conversion is supported is also listed. (An X denotes an invalid operation.)

I/O	U8	U16	S16	U32	S32
U8	X		1.0
U16		X	X
S16	1.0	X	X
U32				X	X
S32				X	X

Down-conversions with VX_CONVERT_POLICY_WRAP follow this equation:

output(x,y) = ((uint8)(input(x,y) >> shift));

Down-conversions with VX_CONVERT_POLICY_SATURATE follow this equation:

int16 value = input(x,y) >> shift;
value = value < 0 ? 0 : value;
value = value > 255 ? 255 : value;
output(x,y) = (uint8)value;

Up-conversions ignore the policy and perform this operation:

output(x,y) = ((int16)input(x,y)) << shift;

The valid values for 'shift' are as specified below, all other values produce undefined behavior.

0 <= shift < 8; 

Functions
vx_node	vxConvertDepthNode (vx_graph graph, vx_image input, vx_image output, vx_enum policy, vx_scalar shift)
	[Graph] Creates a bit-depth conversion node. More...
vx_status	vxuConvertDepth (vx_context context, vx_image input, vx_image output, vx_enum policy, vx_int32 shift)
	[Immediate] Converts the input images bit-depth into the output image. More...

Function Documentation

vx_node vxConvertDepthNode	(	vx_graph	graph,
		vx_image	input,
		vx_image	output,
		vx_enum	policy,
		vx_scalar	shift
	)

[Graph] Creates a bit-depth conversion node.

Parameters

[in]	graph	The reference to the graph.
[in]	input	The input image.
[out]	output	The output image.
[in]	policy	A scalar containing a VX_TYPE_ENUM of the vx_convert_policy_e enumeration.
[in]	shift	A scalar containing a VX_TYPE_INT32 of the shift value.

Returns

vx_node.

Return values

0	Node could not be created.
*	Node handle.

vx_status vxuConvertDepth	(	vx_context	context,
		vx_image	input,
		vx_image	output,
		vx_enum	policy,
		vx_int32	shift
	)

[Immediate] Converts the input images bit-depth into the output image.

Parameters

[in]	context	The reference to the overall context.
[in]	input	The input image.
[out]	output	The output image.
[in]	policy	A vx_convert_policy_e enumeration.
[in]	shift	The shift value.

Returns

A vx_status_e enumeration.

Return values

VX_SUCCESS	Success
*	An error occurred. See vx_status_e..