Making odd numbers required for some filters

Author: rom-thom

image-filtering/config/image_filtering_params.yaml

@@ -33,7 +33,7 @@
       overlap:
         percentage_threshold: 20.0 # Percentage (0-100) to cap the pixel intensity difference
       median_binary: # finds the median of each n x n square around each pixel
-        kernel_size: 3 # must be odd >= 1
+        kernel_size: 3 # must be odd > 1
         threshold: 100 # [0, 255]
         invert: false
       binary:

image-filtering/include/image_filtering/lib/filters/median_binary.hpp

@@ -25,7 +25,9 @@ class MedianBinary : public Filter {
 
 inline void MedianBinary::apply_filter(const cv::Mat& original,
                                        cv::Mat& filtered) const {
-    apply_median(original, filtered, this->filter_params_.kernel_size);
+
+    odd_int kernel_size = odd_int(this->filter_params_.kernel_size);
+    apply_median(original, filtered, int(kernel_size));
     apply_fixed_threshold(filtered, filtered, this->filter_params_.threshold,
                           this->filter_params_.invert);
 }

image-filtering/include/image_filtering/lib/utilities.hpp

@@ -48,5 +48,23 @@ void apply_fixed_threshold(const cv::Mat& img,
                            cv::Mat& filtered,
                            int thresh,
                            bool invert = false);
-}  // namespace vortex::image_filtering
+ 
+// For values that is required to be odd and biger than one
+struct odd_int {
+    int value;
+ 
+    explicit odd_int(int v) : value(v) {
+        if (v <= 1 || (v % 2) == 0) {
+            throw std::invalid_argument("odd_int must be odd and > 1");
+        }
+    }
+ 
+    // Allow passing to APIs that expect int without changing call sites
+    operator int() const noexcept { return value; }
+ 
+
+    int get() const noexcept { return value; }
+};
+ }  // namespace vortex::image_filtering_
+
 #endif  // IMAGE_FILTERING__LIB__UTILITIES_HPP_

image-filtering/src/ros/image_filtering_ros.cpp

@@ -230,12 +230,12 @@ void ImageFilteringNode::image_callback(
     try {
         filter_ptr_->apply_filter(input_image, filtered_image);
     } catch (const cv::Exception& e) {
-        spdlog::error(fmt::format(fmt::fg(fmt::rgb(31, 161, 221)),
+        spdlog::error(fmt::format(fmt::fg(fmt::rgb(255, 0, 0)),
                                   "OpenCV error while applying filter: {}",
                                   e.what()));
         filtered_image = input_image.clone();  // fallback to no filter
     } catch (const std::exception& e) {
-        spdlog::error(fmt::format(fmt::fg(fmt::rgb(31, 161, 221)),
+        spdlog::error(fmt::format(fmt::fg(fmt::rgb(255, 0, 0)),
                                   "Error while applying filter: {}", e.what()));
         filtered_image = input_image.clone();
     }