Class NPPNativeMethods.NPPi.ImageCompression

Image compression primitives.

The JPEG standard defines a flow of level shift, DCT and quantization for forward JPEG transform and inverse level shift, IDCT and de-quantization for inverse JPEG transform. This group has the functions for both forward and inverse functions.

Inheritance

System.Object

NPPNativeMethods.NPPi.ImageCompression

Inherited Members

System.Object.Equals(System.Object)

System.Object.Equals(System.Object, System.Object)

System.Object.GetHashCode()

System.Object.GetType()

System.Object.MemberwiseClone()

System.Object.ReferenceEquals(System.Object, System.Object)

System.Object.ToString()

Namespace: ManagedCuda.NPP

Assembly: NPP.dll

Syntax

public static class ImageCompression

Methods

nppiDCTQuantFwd8x8LS_JPEG_8u16s_C1R(CUdeviceptr, Int32, CUdeviceptr, Int32, CUdeviceptr, NppiSize)

Forward DCT, quantization and level shift part of the JPEG encoding. Input is expected in 8x8 macro blocks and output is expected to be in 64x1 macro blocks.

Declaration

public static NppStatus nppiDCTQuantFwd8x8LS_JPEG_8u16s_C1R(CUdeviceptr pSrc, int nSrcStep, CUdeviceptr pDst, int nDstStep, CUdeviceptr pQuantFwdTable, NppiSize oSizeROI)

Parameters

Type	Name	Description
CUdeviceptr	pSrc	Source-Image Pointer.
System.Int32	nSrcStep	Source-Image Line Step.
CUdeviceptr	pDst	Destination-Image Pointer.
System.Int32	nDstStep	Destination-Image Line Step.
CUdeviceptr	pQuantFwdTable	Forward quantization tables for JPEG encoding created
NppiSize	oSizeROI	Region-of-Interest (ROI).

Returns

Type	Description
NppStatus	Error codes: - #NPP_SIZE_ERROR For negative input height/width or not a multiple of 8 width/height. - #NPP_STEP_ERROR If input image width is not multiple of 8 or does not match ROI. - #NPP_NULL_POINTER_ERROR If the destination pointer is 0.

nppiDCTQuantInv8x8LS_JPEG_16s8u_C1R(CUdeviceptr, Int32, CUdeviceptr, Int32, CUdeviceptr, NppiSize)

Inverse DCT, de-quantization and level shift part of the JPEG decoding. Input is expected in 64x1 macro blocks and output is expected to be in 8x8 macro blocks.

Declaration

public static NppStatus nppiDCTQuantInv8x8LS_JPEG_16s8u_C1R(CUdeviceptr pSrc, int nSrcStep, CUdeviceptr pDst, int nDstStep, CUdeviceptr pQuantInvTable, NppiSize oSizeROI)

Parameters

Type	Name	Description
CUdeviceptr	pSrc	Source-Image Pointer.
System.Int32	nSrcStep	Source-Image Line Step.
CUdeviceptr	pDst	Destination-Image Pointer.
System.Int32	nDstStep	Destination-Image Line Step.
CUdeviceptr	pQuantInvTable	Inverse quantization tables for JPEG decoding created
NppiSize	oSizeROI	Region-of-Interest (ROI).

Returns

Type	Description
NppStatus	Error codes: - #NPP_SIZE_ERROR For negative input height/width or not a multiple of 8 width/height. - #NPP_STEP_ERROR If input image width is not multiple of 8 or does not match ROI. - #NPP_NULL_POINTER_ERROR If the destination pointer is 0.

nppiQuantFwdRawTableInit_JPEG_8u(Byte[], Int32)

Apply quality factor to raw 8-bit quantization table. This is effectively and in-place method that modifies a given raw quantization table based on a quality factor. Note that this method is a host method and that the pointer to the raw quantization table is a host pointer.

Declaration

public static NppStatus nppiQuantFwdRawTableInit_JPEG_8u(byte[] hpQuantRawTable, int nQualityFactor)

Parameters

Type	Name	Description
System.Byte[]	hpQuantRawTable	Raw quantization table.
System.Int32	nQualityFactor	Quality factor for the table. Range is [1:100].

Returns

Type	Description
NppStatus	Error code: #NPP_NULL_POINTER_ERROR is returned if hpQuantRawTable is 0.

nppiQuantFwdTableInit_JPEG_8u16u(Byte[], UInt16[])

Initializes a quantization table for nppiDCTQuantFwd8x8LS_JPEG_8u16s_C1R(). The method creates a 16-bit version of the raw table and converts the data order from zigzag layout to original row-order layout since raw quantization tables are typically stored in zigzag format. This method is a host method. It consumes and produces host data. I.e. the pointers passed to this function must be host pointers. The resulting table needs to be transferred to device memory in order to be used with nppiDCTQuantFwd8x8LS_JPEG_8u16s_C1R() function.

Declaration

public static NppStatus nppiQuantFwdTableInit_JPEG_8u16u(byte[] hpQuantRawTable, ushort[] hpQuantFwdRawTable)

Parameters

Type	Name	Description
System.Byte[]	hpQuantRawTable	Host pointer to raw quantization table as returned by
System.UInt16[]	hpQuantFwdRawTable	Forward quantization table for use with nppiDCTQuantFwd8x8LS_JPEG_8u16s_C1R().

Returns

Type	Description
NppStatus	Error code: #NPP_NULL_POINTER_ERROR pQuantRawTable is 0.

nppiQuantInvTableInit_JPEG_8u16u(Byte[], UInt16[])

Initializes a quantization table for nppiDCTQuantInv8x8LS_JPEG_16s8u_C1R(). The nppiDCTQuantFwd8x8LS_JPEG_8u16s_C1R() method uses a quantization table in a 16-bit format allowing for faster processing. In addition it converts the data order from zigzag layout to original row-order layout. Typically raw quantization tables are stored in zigzag format. This method is a host method and consumes and produces host data. I.e. the pointers passed to this function must be host pointers. The resulting table needs to be transferred to device memory in order to be used with nppiDCTQuantFwd8x8LS_JPEG_8u16s_C1R() function.

Declaration

public static NppStatus nppiQuantInvTableInit_JPEG_8u16u(byte[] hpQuantRawTable, ushort[] hpQuantFwdRawTable)

Parameters

Type	Name	Description
System.Byte[]	hpQuantRawTable	Raw quantization table.
System.UInt16[]	hpQuantFwdRawTable	Inverse quantization table.

Returns

Type	Description
NppStatus	#NPP_NULL_POINTER_ERROR pQuantRawTable or pQuantFwdRawTable is0.