Enhances the contrast of a color image

# Imagick::contrastStretchImage

(PECL imagick 2.0.0)

Imagick::contrastStretchImage — Enhances the contrast of a color image

### Descrierea

Imagick::contrastStretchImage ( float `$black_point` , float `$white_point` [, int `$channel` = Imagick::CHANNEL_DEFAULT ] ) : bool

Enhances the contrast of a color image by adjusting the pixels color to span the entire range of colors available. Această metodă este disponibilă dacă Imagick a fost compilat cu ImageMagick de versiunea 6.2.9 sau ulterior.

### Parametri

`black_point`

  The black point.

`white_point`

  The white point.

`channel`

  Provide any channel constant that is valid for your channel mode. To apply to more than one channel, combine channeltype constants using bitwise operators. `Imagick::CHANNEL_ALL`. Refer to this list of channel constants.

### Valorile întoarse

Întoarce `TRUE` în caz de succes.