Method: Magick::Image#sigmoidal_contrast_channel

Defined in:
ext/RMagick/rmimage.c

#sigmoidal_contrast_channel(*args) ⇒ Object

Call SigmoidalContrastImageChannel.

Ruby usage:

- @verbatim Image#sigmoidal_contrast_channel @endverbatim
- @verbatim Image#sigmoidal_contrast_channel(contrast) @endverbatim
- @verbatim Image#sigmoidal_contrast_channel(contrast, midpoint) @endverbatim
- @verbatim Image#sigmoidal_contrast_channel(contrast, midpoint, sharpen) @endverbatim
- @verbatim Image#sigmoidal_contrast_channel(contrast, midpoint, sharpen, channel) @endverbatim
- @verbatim Image#sigmoidal_contrast_channel(contrast, midpoint, sharpen, channel, ...) @endverbatim

Notes:

- Default contrast is 3.0
- Default midpoint is 50.0
- Default sharpen is false
- Default channel is AllChannels

Parameters:

  • argc —

    number of input arguments

  • argv —

    array of input arguments

  • self —

    this object

Returns:

  • a new image


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# File 'ext/RMagick/rmimage.c', line 12055

VALUE
Image_sigmoidal_contrast_channel(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    MagickBooleanType sharpen = MagickFalse;
    double contrast = 3.0;
    double midpoint = 50.0;
    ChannelType channels;

    image = rm_check_destroyed(self);
    channels = extract_channels(&argc, argv);

    switch (argc)
    {
        case 3:
            sharpen  = (MagickBooleanType) RTEST(argv[2]);
        case 2:
            midpoint = NUM2DBL(argv[1]);
        case 1:
            contrast = NUM2DBL(argv[0]);
        case 0:
            break;
        default:
            raise_ChannelType_error(argv[argc-1]);
            break;
    }

    new_image = rm_clone_image(image);

    (void) SigmoidalContrastImageChannel(new_image, channels, sharpen, contrast, midpoint);
    rm_check_image_exception(new_image, DestroyOnError);

    return rm_image_new(new_image);
}