make size of minimum face variable

src/lib.rs

@@ -43,6 +43,7 @@ pub extern "C" fn scan_image(haar: *mut visualhaar::HaarClassifier,
                             input: *const u8,
                             buffer: *mut u8,
                             length: usize,
+                            min_face_factor: usize,
                             debug: bool) {
     if haar.is_null() || input.is_null() || buffer.is_null() {
         return;
@@ -72,7 +73,7 @@ pub extern "C" fn scan_image(haar: *mut visualhaar::HaarClassifier,
         }
     }
 
-    let image = haar.scan_image(input_frame, &hm).unwrap().dynamic_img;
+    let image = haar.scan_image(input_frame, &hm,min_face_factor as u32).unwrap().dynamic_img;
     let rgb_img = image.to_rgb();
     // image.save("/home/ruben/Documents/Projecten/2020/rust/lena_orig-output-lib.png");
     info!("Scanning for faces took done");

src/test.rs

@@ -47,7 +47,7 @@ fn main() {
             let i = ib.as_rgb8().unwrap().clone();
             let hm = Some(heatmap::Heatmap::new(heatmap::ColorMaps::Plasma));
             let mut sw = Stopwatch::start_new();
-            let image = haar.scan_image(i, &hm).unwrap().dynamic_img;
+            let image = haar.scan_image(i, &hm, 4).unwrap().dynamic_img;
             info!("Scanning for faces took {}ms", sw.elapsed_ms());
             image.save("test-output.png");
 

src/visualhaar.rs

@@ -342,7 +342,8 @@ impl HaarClassifier {
     // }
 
     /// take an ImageBuffer and scan it for faces.
-    pub fn scan_image(&self, frame: image::ImageBuffer<image::Rgb<u8>, Vec<u8>>, heatmap: &Option<heatmap::Heatmap>) -> Result<Outcome, String> {
+    /// min_face_factor parameter gives starting size of scan window (frame height / factor). So higher number scans for smaller faces.
+    pub fn scan_image(&self, frame: image::ImageBuffer<image::Rgb<u8>, Vec<u8>>, heatmap: &Option<heatmap::Heatmap>, min_face_factor: u32) -> Result<Outcome, String> {
 
 
         let sw = Stopwatch::start_new();
@@ -365,7 +366,7 @@ impl HaarClassifier {
         // let rect = integral.slice(s![3..5, 2..4]);
 
         // let min_size = self.width;
-        let min_size = frame.height() / 3; // TODO: Make min face size (or factor) variable
+        let min_size = frame.height() / min_face_factor; // TODO: Make min face size (or factor) variable
         let max_window_size = std::cmp::min(img_bw.dimensions().0, img_bw.dimensions().1) as usize;
         
         let mut window_size: usize = min_size.clone() as usize;