man pages section 3: Multimedia Library Functions

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Updated: July 2014
 
 

mlib_ImageReformat(3MLIB)

Name

mlib_ImageReformat - image data buffer reformat

Synopsis

cc [ flag... ] file... –lmlib [ library... ]
#include <mlib.h>

mlib_status mlib_ImageReformat(void **dstData, const void **srcData,
     mlib_s32 numBands, mlib_s32 xSize, mlib_s32 ySize,
     mlib_type dstDataType, const mlib_s32 *dstBandoffsets,
     mlib_s32 dstScanlinestride, mlib_s32 dstPixelstride,
     mlib_type srcDataType, const mlib_s32 *srcBandoffsets,
     mlib_s32 srcScanlinestride, mlib_s32 srcPixelstride);

Description

The mlib_ImageReformat() function copies and casts, if needed, an image from one buffer to another. The formats and data types of the two buffers may be different.

dstPixel[x][y][i] = (dstDataType) srcPixel[x][y][i]

where the values of a pixel at position (x, y) and in channel i are:

srcPixel[x][y][i] = srcData[i][srcBandoffsets[i] +
                               srcScanlinestride*y +
                               srcPixelstride*x]

dstPixel[x][y][i] = dstData[i][dstBandoffsets[i] +
                               dstScanlinestride*y +
                               dstPixelstride*x]

It is the user's responsibility to make sure that the data buffers supplied are suitable for this operation. The srcData and dstData can have 1, 2, 3, or 4 channels, and they must have the same number of channels. The srcDataType and dstDataType can be MLIB_BYTE, MLIB_SHORT , MLIB_USHORT, MLIB_INT, MLIB_FLOAT, or MLIB_DOUBLE.

The conversions between different data types are implemented as described in the following table:

Source Type
Dest. Type
Action
MLIB_SHORT
MLIB_BYTE
(mlib_u8)clamp(x, 0, 255)
MLIB_USHORT
MLIB_BYTE
(mlib_u8)clamp(x, 0, 255)
MLIB_INT
MLIB_BYTE
(mlib_u8)clamp(x, 0, 255)
MLIB_FLOAT
MLIB_BYTE
(mlib_u8)clamp(x, 0, 255)
MLIB_DOUBLE
MLIB_BYTE
(mlib_u8)clamp(x, 0, 255)
MLIB_BYTE
MLIB_SHORT
(mlib_s16)x
MLIB_USHORT
MLIB_SHORT
(mlib_s16)clamp(x, -32768, 32767)
MLIB_INT
MLIB_SHORT
(mlib_s16)clamp(x, -32768, 32767)
MLIB_FLOAT
MLIB_SHORT
(mlib_s16)clamp(x, -32768, 32767)
MLIB_DOUBLE
MLIB_SHORT
(mlib_s16)clamp(x, -32768, 32767)
MLIB_BYTE
MLIB_USHORT
(mlib_u16)x
MLIB_SHORT
MLIB_USHORT
(mlib_u16)clamp(x, 0, 65535)
MLIB_INT
MLIB_USHORT
(mlib_u16)clamp(x, 0, 65535)
MLIB_FLOAT
MLIB_USHORT
(mlib_u16)clamp(x, 0, 65535)
MLIB_DOUBLE
MLIB_USHORT
(mlib_u16)clamp(x, 0, 65535)
MLIB_BYTE
MLIB_INT
(mlib_s32)x
MLIB_SHORT
MLIB_INT
(mlib_s32)x
MLIB_USHORT
MLIB_INT
(mlib_s32)x
MLIB_FLOAT
MLIB_INT
(mlib_s32)clamp(x, -2147483647-1, 2147483647)
MLIB_DOUBLE
MLIB_INT
(mlib_s32)clamp(x, -2147483647-1, 2147483647)
MLIB_BYTE
MLIB_FLOAT
(mlib_f32)x
MLIB_SHORT
MLIB_FLOAT
(mlib_f32)x
MLIB_USHORT
MLIB_FLOAT
(mlib_f32)x
MLIB_INT
MLIB_FLOAT
(mlib_f32)x
MLIB_DOUBLE
MLIB_FLOAT
(mlib_f32)x
MLIB_BYTE
MLIB_DOUBLE
(mlib_d64)x
MLIB_SHORT
MLIB_DOUBLE
(mlib_d64)x
MLIB_USHORT
MLIB_DOUBLE
(mlib_d64)x
MLIB_INT
MLIB_DOUBLE
(mlib_d64)x
MLIB_FLOAT
MLIB_DOUBLE
(mlib_d64)x

The actions are defined in C-style pseudo-code. All type casts follow the rules of standard C. clamp() can be defined as a macro: #define clamp(x, low, high) (((x) < (low)) ? (low) : (((x) > (high)) ? (high) : (x)))

Parameters

The function takes the following arguments:

dstData

The pointer to the destination image data buffer.

srcData

The pointer to the source image data buffer.

numBands

The number of channels of the image data buffers.

xSize

The width of the image.

ySize

The height of the image.

dstDataType

The data type of the dstData buffer.

dstBandoffsets

The initial pixel's offsets in the dstData buffer in terms of destination data buffer elements.

dstScanlinestride

The scanline stride of the dstData buffer in terms of destination data buffer elements.

dstPixelstride

The pixel stride of the dstData buffer in terms of destination data buffer elements.

srcDataType

The data type of the srcData buffer.

srcBandoffsets

The initial pixel's offsets in the srcData buffer in terms of source data buffer elements.

srcScanlinestride

The scanline stride of the srcData buffer in terms of source data buffer elements.

srcPixelstride

The pixel stride of the srcData buffer in terms of source data buffer elements.

Return Values

The function returns MLIB_SUCCESS if successful. Otherwise it returns MLIB_FAILURE.

Attributes

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE
ATTRIBUTE VALUE
Interface Stability
Committed
MT-Level
MT-Safe

See also

mlib_ImageDataTypeConvert(3MLIB), attributes (5)