IM: Tone Gamut Operations

IM - Imaging Libray

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Tone Gamut Operations
[Image Processing]

Detailed Description

Operations that try to preserve the min-max interval in the output (the dynamic range).
See im_process_pon.h


Enumerations

enum  imToneGamut {
  IM_GAMUT_NORMALIZE, IM_GAMUT_POW, IM_GAMUT_LOG, IM_GAMUT_EXP,
  IM_GAMUT_INVERT, IM_GAMUT_ZEROSTART, IM_GAMUT_SOLARIZE, IM_GAMUT_SLICE,
  IM_GAMUT_EXPAND, IM_GAMUT_CROP, IM_GAMUT_BRIGHTCONT
}

Functions

void imProcessToneGamut (const imImage *src_image, imImage *dst_image, int op, float *param)
void imProcessUnNormalize (const imImage *src_image, imImage *dst_image)
void imProcessDirectConv (const imImage *src_image, imImage *dst_image)
void imProcessNegative (const imImage *src_image, imImage *dst_image)

Enumeration Type Documentation

enum imToneGamut
 

Tone Gamut Operations.

Enumeration values:
IM_GAMUT_NORMALIZE  normalize = (a-min) / (max-min) (destiny image must be IM_FLOAT)
IM_GAMUT_POW  pow = ((a-min) / (max-min))^gamma * (max-min) + min
param[0]=gamma
IM_GAMUT_LOG  log = log(K * (a-min) / (max-min) + 1))*(max-min)/log(K+1) + min
param[0]=K (K>0)
IM_GAMUT_EXP  exp = (exp(K * (a-min) / (max-min)) - 1))*(max-min)/(exp(K)-1) + min
param[0]=K
IM_GAMUT_INVERT  invert = max - (a-min)
IM_GAMUT_ZEROSTART  zerostart = a - min
IM_GAMUT_SOLARIZE  solarize = a < level ? a: (level * (max-min) - a * (level-min)) / (max-level)
param[0]=level percentage (0-100) relative to min-max
photography solarization effect.
IM_GAMUT_SLICE  slice = start < a || a > end ? min: binarize? max: a
param[0]=start, param[1]=end, param[2]=binarize
IM_GAMUT_EXPAND  expand = a < start ? min: a > end ? max : (a-start)*(max-min)/(end-start) + min
param[0]=start, param[1]=end
IM_GAMUT_CROP  crop = a < start ? start: a > end ? end : a
param[0]=start, param[1]=end
IM_GAMUT_BRIGHTCONT  brightcont = a < min ? min: a > max ? max: a * tan(c_a) + b_s + (max-min)*(1 - tan(c_a))/2
param[0]=bright_shift (-100%..+100%), param[1]=contrast_factor (-100%..+100%)
change brightness and contrast simultaneously. 
00361                  {
00362   IM_GAMUT_NORMALIZE, /**< normalize = (a-min) / (max-min)     (destiny image must be IM_FLOAT)   */
00363   IM_GAMUT_POW,       /**< pow       = ((a-min) / (max-min))^gamma * (max-min) + min                  \n
00364                                        param[0]=gamma                                             */
00365   IM_GAMUT_LOG,       /**< log       = log(K * (a-min) / (max-min) + 1))*(max-min)/log(K+1) + min     \n
00366                                        param[0]=K     (K>0)                                       */
00367   IM_GAMUT_EXP,       /**< exp       = (exp(K * (a-min) / (max-min)) - 1))*(max-min)/(exp(K)-1) + min \n
00368                                        param[0]=K                                                 */
00369   IM_GAMUT_INVERT,    /**< invert    = max - (a-min)                                              */
00370   IM_GAMUT_ZEROSTART, /**< zerostart = a - min                                                    */
00371   IM_GAMUT_SOLARIZE,  /**< solarize  = a < level ?  a:  (level * (max-min) - a * (level-min)) / (max-level) \n
00372                                        param[0]=level percentage (0-100) relative to min-max      \n
00373                                        photography solarization effect. */
00374   IM_GAMUT_SLICE,     /**< slice     = start < a || a > end ?  min:  binarize?  max: a                     \n
00375                                        param[0]=start,  param[1]=end,  param[2]=binarize          */
00376   IM_GAMUT_EXPAND,    /**< expand    = a < start ?  min: a > end ? max :  (a-start)*(max-min)/(end-start) + min  \n
00377                                        param[0]=start,  param[1]=end                              */
00378   IM_GAMUT_CROP,      /**< crop      = a < start ?  start: a > end ? end : a                                        \n
00379                                        param[0]=start,  param[1]=end                              */
00380   IM_GAMUT_BRIGHTCONT /**< brightcont = a < min ?  min:  a > max ?  max:  a * tan(c_a) + b_s + (max-min)*(1 - tan(c_a))/2  \n
00381                                         param[0]=bright_shift (-100%..+100%),  param[1]=contrast_factor (-100%..+100%)     \n
00382                                         change brightness and contrast simultaneously. */
00383 };

Function Documentation

void imProcessToneGamut (  const imImage *  src_image,
imImage *  dst_image,
int  op,
float *  param
) 
 

Apply a gamut operation with arguments.
Supports all data types except IM_COMPLEX.
The linear operation do a special convertion when min > 0 and max < 1, it forces min=0 and max=1.
IM_BYTE images have min=0 and max=255 always.
Can be done in place. When there is no extra params use NULL.

void imProcessUnNormalize (  const imImage *  src_image,
imImage *  dst_image
) 
 

Converts from (0-1) to (0-255), crop out of bounds values.
Source image must be IM_FLOAT, and destiny image must be IM_BYTE.

void imProcessDirectConv (  const imImage *  src_image,
imImage *  dst_image
) 
 

Directly converts IM_USHORT, IM_INT and IM_FLOAT into IM_BYTE images.
This can also be done using imConvertDataType with IM_CAST_DIRECT.

void imProcessNegative (  const imImage *  src_image,
imImage *  dst_image
) 
 

A negative effect. Uses imProcessToneGamut with IM_GAMUT_INVERT for non MAP images.
Supports all color spaces and all data types except IM_COMPLEX.


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