man pages section 3: Multimedia Library Functions

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Updated: July 2014
 
 

mlib_ImageThresh4_Fp (3MLIB)

Name

mlib_ImageThresh4_Fp - image thresholding

Synopsis

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

mlib_status mlib_ImageThresh4_Fp(mlib_image *dst, const mlib_image *src,
     const mlib_d64 *thigh, const mlib_d64 *tlow, const mlib_d64 *ghigh,
     const mlib_d64 *glow);

Description

The mlib_ImageThresh4_Fp() function compares each pixel in the source image to two threshold values, tlow and thigh. If the pixel is less than the lower threshold value, tlow, then the destination pixel is set to the lower output level, glow. If the pixel is greater than the higher threshold value, thigh, then the destination pixel is set to the higher output level, ghigh. Otherwise, the destination pixel is set to the value of the source pixel.

It uses the following equation:

dst[x][y][i] = glow[i]       if src[x][y][i] < tlow[i]
dst[x][y][i] = src[x][y][i]  if tlow[i] ≤ src[x][y][i] ≤ thigh[i]
dst[x][y][i] = ghigh[i]      if src[x][y][i] > thigh[i]

Parameters

The function takes the following arguments:

dst

Pointer to destination image.

src

Pointer to source image.

thigh

High threshold value. thigh[i] holds the high threshold for channel i.

tlow

Low threshold value. tlow[i] holds the low threshold for channel i.

ghigh

High output grayscale level. ghigh[i] holds the high output grayscale level for channel i.

glow

Low output grayscale level. glow[i] holds the low output grayscale level for channel i.

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_ImageThresh1(3MLIB), mlib_ImageThresh1_Fp(3MLIB), mlib_ImageThresh1_Fp_Inp(3MLIB), mlib_ImageThresh1_Inp(3MLIB), mlib_ImageThresh2(3MLIB), mlib_ImageThresh2_Fp(3MLIB), mlib_ImageThresh2_Fp_Inp(3MLIB), mlib_ImageThresh2_Inp(3MLIB), mlib_ImageThresh3(3MLIB), mlib_ImageThresh3_Fp(3MLIB), mlib_ImageThresh3_Fp_Inp(3MLIB), mlib_ImageThresh3_Inp(3MLIB), mlib_ImageThresh4(3MLIB), mlib_ImageThresh4_Fp_Inp(3MLIB), mlib_ImageThresh4_Inp(3MLIB), mlib_ImageThresh5(3MLIB), mlib_ImageThresh5_Fp(3MLIB), mlib_ImageThresh5_Fp_Inp(3MLIB), mlib_ImageThresh5_Inp(3MLIB), attributes(5)