Method: Magick::Image#random_threshold_channel

Defined in:
ext/RMagick/rmimage.c

#random_threshold_channel(*args) ⇒ Object

Call RandomThresholdImageChannel.

Ruby usage:

- @verbatim Image#random_threshold_channel(geometry_str) @endverbatim
- @verbatim Image#random_threshold_channel(geometry_str, channel) @endverbatim
- @verbatim Image#random_threshold_channel(geometry_str, channel, ...) @endverbatim

Notes:

- Default channel is AllChannels

Parameters:

  • argc —

    number of input arguments

  • argv —

    array of input arguments

  • self —

    this object

Returns:

  • a new image

[View source]

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# File 'ext/RMagick/rmimage.c', line 10469

VALUE
Image_random_threshold_channel(int argc, VALUE *argv, VALUE self)
{
    Image *image, *new_image;
    ChannelType channels;
    char *thresholds;
    volatile VALUE geom_str;
    ExceptionInfo exception;

    image = rm_check_destroyed(self);

    channels = extract_channels(&argc, argv);

    // There must be 1 remaining argument.
    if (argc == 0)
    {
        rb_raise(rb_eArgError, "missing threshold argument");
    }
    else if (argc > 1)
    {
        raise_ChannelType_error(argv[argc-1]);
    }

    // Accept any argument that has a to_s method.
    geom_str = rm_to_s(argv[0]);
    thresholds = StringValuePtr(geom_str);

    new_image = rm_clone_image(image);

    GetExceptionInfo(&exception);

    (void) RandomThresholdImageChannel(new_image, channels, thresholds, &exception);
    rm_check_exception(&exception, new_image, DestroyOnError);

    (void) DestroyExceptionInfo(&exception);

    return rm_image_new(new_image);
}