Fixes #983. blur 0.0 panic

src/imageops/mod.rs

@@ -286,6 +286,7 @@ where
 mod tests {
 
     use super::overlay;
+    use crate::RgbaImage;
     use crate::ImageBuffer;
     use crate::color::Rgb;
 
@@ -366,4 +367,11 @@ mod tests {
         assert_eq!(img.get_pixel(0, 0), &start);
         assert_eq!(img.get_pixel(0, img.height() - 1), &end);
     }
+
+    #[test]
+    /// Test blur doens't panick when passed 0.0
+    fn test_blur_zero() {
+        let image = RgbaImage::new(50, 50);
+        let _ = super::blur(&image, 0.0);
+    }
 }

src/imageops/sample.rs

@@ -755,7 +755,7 @@ pub fn blur<I: GenericImageView>(
 where
     I::Pixel: 'static,
 {
-    let sigma = if sigma < 0.0 { 1.0 } else { sigma };
+    let sigma = if sigma <= 0.0 { 1.0 } else { sigma };
 
     let mut method = Filter {
         kernel: Box::new(|x| gaussian(x, sigma)),