Akaze: Fixed simple Scharr filters.

rust-cv · Jun 13, 2023 · 33383f7 · 33383f7
1 parent a94a9a4
commit 33383f7
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Showing 3 changed files with 22 additions and 4 deletions.
diff --git a/akaze/src/contrast_factor.rs b/akaze/src/contrast_factor.rs
@@ -22,8 +22,8 @@ pub fn compute_contrast_factor(
     let mut num_points: f64 = 0.0;
     let mut histogram = vec![0; num_bins];
     let gaussian = gaussian_blur(image, gradient_histogram_scale as f32);
-    let Lx = crate::derivatives::scharr_horizontal(&gaussian, 1);
-    let Ly = crate::derivatives::scharr_vertical(&gaussian, 1);
+    let Lx = crate::derivatives::simple_scharr_horizontal(&gaussian);
+    let Ly = crate::derivatives::simple_scharr_vertical(&gaussian);
     let hmax = (1..gaussian.height() - 1)
         .flat_map(|y| (1..gaussian.width() - 1).map(move |x| (x, y)))
         .map(|(x, y)| Lx.get(x, y).powi(2) as f64 + Ly.get(x, y).powi(2) as f64)

diff --git a/akaze/src/derivatives.rs b/akaze/src/derivatives.rs
@@ -1,6 +1,24 @@
 use crate::image::{fill_border, GrayFloatImage};
 use ndarray::{s, Array2, ArrayView2, ArrayViewMut2};
 
+pub fn simple_scharr_horizontal(image: &GrayFloatImage) -> GrayFloatImage {
+    // similar to cv::Scharr with xorder=1, yorder=0, scale=1, delta=0
+    GrayFloatImage(imageproc::filter::separable_filter(
+        &image.0,
+        &[-1., 0., 1.],
+        &[3., 10., 3.],
+    ))
+}
+
+pub fn simple_scharr_vertical(image: &GrayFloatImage) -> GrayFloatImage {
+    // similar to cv::Scharr with xorder=0, yorder=1, scale=1, delta=0
+    GrayFloatImage(imageproc::filter::separable_filter(
+        &image.0,
+        &[3., 10., 3.],
+        &[-1., 0., 1.],
+    ))
+}
+
 /// Compute the Scharr derivative horizontally
 ///
 /// The implementation of this function is using a separable kernel, for speed.

diff --git a/akaze/src/lib.rs b/akaze/src/lib.rs
@@ -195,9 +195,9 @@ impl Akaze {
             }
             evolutions[i].Lsmooth = gaussian_blur(&evolutions[i].Lt, 1.0f32);
             trace!("Gaussian blur finished.");
-            evolutions[i].Lx = derivatives::scharr_horizontal(&evolutions[i].Lsmooth, 1);
+            evolutions[i].Lx = derivatives::simple_scharr_horizontal(&evolutions[i].Lsmooth);
             trace!("Computing derivative Lx done.");
-            evolutions[i].Ly = derivatives::scharr_vertical(&evolutions[i].Lsmooth, 1);
+            evolutions[i].Ly = derivatives::simple_scharr_vertical(&evolutions[i].Lsmooth);
             trace!("Computing derivative Ly done.");
             evolutions[i].Lflow = pm_g2(&evolutions[i].Lx, &evolutions[i].Ly, contrast_factor);
             trace!("Lflow finished.");