mlib_ImageLookUpMask

- table lookup with mask

Synopsis

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

mlib_status mlib_ImageLookUpMask(mlib_image *dst, const mlib_image *src,
     const void **table, mlib_s32 channels, mlib_s32 cmask);

Description

The mlib_ImageLookUpMask() function maps the source image to the destination image by using the user-specified lookup table and applying a channel mask.

The source and destination images must have the same width and height. The source image can be a single channel image or can have the same number of channels as the destination image. One of the following equations is used accordingly:

dst[x][y][i] = table[i][src[x][y][0]]
dst[x][y][i] = table[i][src[x][y][i]]

The source and destination images can have different data types. See the following table for available variations of the table lookup function on image types:

[*] Each row represents a source data type. Each column represents a destination data type.

Parameters

The function takes the following arguments:

dst

Pointer to destination image.

src

Pointer to source image.

table

Pointer to lookup table. The data type of the lookup table is the same as the destination image. The number of entries in the lookup table is determined by the type of the input image. The format of the lookup table is:

table[channel][index]

The MLIB_BIT type entries are indexed from 0 to 1. The MLIB_BYTE type entries are indexed from 0 to 255. The MLIB_SHORT type entries are indexed from -32768 to -1, then from 0 to 32767. The MLIB_USHORT type entries are indexed from 0 to 65535. The MLIB_INT type entries are indexed from -2147483648 to -1, and then from 0 to 2147483647.

channels

Number of channels in the lookup table. If the number of channels is equal to 1, then the same table is applied to all channels. Otherwise, the number of channels must be no less than the number of valid 1s in the channel mask.

cmask

Channel mask. Each bit of the mask represents a channel of an image or a lookup table. Only the rightmost four bits of cmask are considered, where the least significant bit of cmask is for the last channel. The channels corresponding to 0 bits of cmask are not processed or used. cmask is always applied to the destination image dst. If the source image src has the same number of channels as dst, then cmask is also applied to src. Otherwise, each channel of src is used for each cmask bit with a value of 1, in this order: the first channel for the first 1 from the left in cmask. If src has only one channel, then the same src channel is used for every cmask bit with a value of 1. If the lookup table has the same number of channels as dst, then cmask is also applied to table. Otherwise, each table channel is used for each cmask bit with a value of 1, in this order: the first channel for the first 1 from the left in cmask. If table has only one channel, then the same table channel is used for every cmask bit with a value of 1.

Return Values

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

Attributes

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

See Also

mlib_ImageLookUp(3MLIB), mlib_ImageLookUp_Inp(3MLIB), mlib_ImageLookUp2(3MLIB), attributes(5)