Trait rustface::Detector

pub trait Detector {
    fn detect(&mut self, image: &ImageData<'_>) -> Vec<FaceInfo>;
    fn set_window_size(&mut self, wnd_size: u32);
    fn set_slide_window_step(&mut self, step_x: u32, step_y: u32);
    fn set_min_face_size(&mut self, min_face_size: u32);
    fn set_max_face_size(&mut self, max_face_size: u32);
    fn set_pyramid_scale_factor(&mut self, scale_factor: f32);
    fn set_score_thresh(&mut self, thresh: f64);
}

Required Methods

fn detect(&mut self, image: &ImageData<'_>) -> Vec<FaceInfo>

Detect faces on input image.

(1) The input image should be gray-scale, i.e. num_channels set to 1. (2) Currently this function does not give the Euler angles, which are left with invalid values.

Panics

Panics if image is not a legal image, e.g. it

• is not gray-scale (num_channels is not equal to 1)
• has width or height equal to 0

fn set_window_size(&mut self, wnd_size: u32)

Set the size of the sliding window.

The minimum size is constrained as no smaller than 20.

Panics

Panics if wnd_size is less than 20.

fn set_slide_window_step(&mut self, step_x: u32, step_y: u32)

Set the sliding window step in horizontal and vertical directions.

The steps should take positive values. Usually a step of 4 is a reasonable choice.

Panics

Panics if step_x or step_y is less than or equal to 0.

fn set_min_face_size(&mut self, min_face_size: u32)

Set the minimum size of faces to detect.

The minimum size is constrained as no smaller than 20.

Panics

Panics if min_face_size is less than 20.

fn set_max_face_size(&mut self, max_face_size: u32)

Set the maximum size of faces to detect.

The maximum face size actually used is computed as the minimum among: user specified size, image width, image height.

fn set_pyramid_scale_factor(&mut self, scale_factor: f32)

Set the factor between adjacent scales of image pyramid.

The value of the factor lies in (0.1, 0.99). For example, when it is set as 0.5, an input image of size w x h will be resized to 0.5w x 0.5h, 0.25w x 0.25h, 0.125w x 0.125h, etc.

Panics

Panics if scale_factor is less than 0.01 or greater than 0.99

fn set_score_thresh(&mut self, thresh: f64)

Set the score threshold of detected faces.

Detections with scores smaller than the threshold will not be returned. Typical threshold values include 0.95, 2.8, 4.5. One can adjust the threshold based on his or her own test set.

Smaller values result in more detections (possibly increasing the number of false positives), larger values result in fewer detections (possibly increasing the number of false negatives).

Panics

Panics if thresh is less than or equal to 0.

Implementors