Create example binary for Canny

examples/canny.rs

@@ -0,0 +1,38 @@
+use ccvl::filter;
+use ccvl::image::*;
+
+fn main() -> std::process::ExitCode {
+    let args = std::env::args().collect::<Vec<String>>();
+    if args.len() != 3 {
+        println!("Usage: {} IN OUT", args[0].as_str());
+        return std::process::ExitCode::FAILURE;
+    }
+
+    let input_path = args[1].as_str();
+    let output_path = args[2].as_str();
+
+    match Image::load::<Farbfeld>(input_path) {
+        Err(Error::Invalid) => {
+            println!("{} is not a valid image", input_path);
+            std::process::ExitCode::FAILURE
+        }
+        Err(Error::Io(err)) => {
+            println!("I/O error loading image {}: {}", input_path, err);
+            std::process::ExitCode::FAILURE
+        }
+        Ok(img) => {
+            let result = filter::canny(img.map(|p| Luminance::from(p)))
+                .map(|p| p.into());
+            match result.save::<Farbfeld>(output_path) {
+                Err(err) => {
+                    println!(
+                        "I/O error saving image {}: {}",
+                        output_path, err
+                    );
+                    std::process::ExitCode::FAILURE
+                }
+                Ok(()) => std::process::ExitCode::SUCCESS,
+            }
+        }
+    }
+}