Imagick::shearImage
Imagick::sketchImage
The Imagick class
PHP Manual

# Imagick::sigmoidalContrastImage

(PECL imagick 2.0.0)

Imagick::sigmoidalContrastImage — Adjusts the contrast of an image

### Descrição

bool Imagick::sigmoidalContrastImage ( bool `$sharpen` , float `$alpha` , float `$beta` [, int `$channel` = Imagick::CHANNEL_ALL ] )
Aviso

Esta função não está documentada; somente a lista de argumentos está disponível.

Adjusts the contrast of an image with a non-linear sigmoidal contrast algorithm. Increase the contrast of the image using a sigmoidal transfer function without saturating highlights or shadows. Contrast indicates how much to increase the contrast (0 is none; 3 is typical; 20 is pushing it); mid-point indicates where midtones fall in the resultant image (0 is white; 50 is middle-gray; 100 is black). Set sharpen to `TRUE` to increase the image contrast otherwise the contrast is reduced.

### Parâmetros

`sharpen`

`alpha`

`beta`

`channel`

### Valor Retornado

Retorna `TRUE` em sucesso.

### Erros

Dispara ImagickException em erro.

Imagick::shearImage
Imagick::sketchImage
The Imagick class
PHP Manual