fix: fix blendings and change handling gray value

Author: paithiov909

DESCRIPTION

@@ -1,7 +1,7 @@
 Type: Package
 Package: aznyan
 Title: Image Filters with 'OpenCV'
-Version: 26.02.12
+Version: 26.02.13
 Authors@R: c(
     person("Akiru", "Kato", , "paithiov909@gmail.com", role = c("aut", "cre")),
     person("Jeroen", "Ooms", role = "cph")

NAMESPACE

@@ -5,6 +5,7 @@ export(as_recordedplot)
 export(aznyan_num_threads)
 export(bilateral_filter)
 export(blend_add)
+export(blend_alpha)
 export(blend_average)
 export(blend_colorburn)
 export(blend_colordodge)
@@ -19,7 +20,6 @@ export(blend_lighten)
 export(blend_linearlight)
 export(blend_luminosity)
 export(blend_multiply)
-export(blend_over)
 export(blend_overlay)
 export(blend_pinlight)
 export(blend_screen)

R/blend.R

@@ -10,9 +10,9 @@ NULL
 
 #' @rdname blend
 #' @export
-blend_over <- function(src, dst) {
+blend_alpha <- function(src, dst) {
   check_nr_dim(src, dst)
-  as_nr(azny_blend_over(src, dst, nrow(src), ncol(src)))
+  as_nr(azny_blend_alpha(src, dst, nrow(src), ncol(src)))
 }
 
 #' @rdname blend

R/cpp11.R

@@ -1,7 +1,7 @@
 # Generated by cpp11: do not edit by hand
 
-azny_blend_over <- function(src, dst, height, width) {
-  .Call(`_aznyan_azny_blend_over`, src, dst, height, width)
+azny_blend_alpha <- function(src, dst, height, width) {
+  .Call(`_aznyan_azny_blend_alpha`, src, dst, height, width)
 }
 
 azny_blend_darken <- function(src, dst, height, width) {

man/blend.Rd

@@ -2,6 +2,8 @@
 #include <opencv2/opencv.hpp>
 #include <cpp11.hpp>
 
+namespace {
+
 inline float srgb_to_linear(float x) {
   if (x <= 0.04045f) return x / 12.92f;
   return std::pow((x + 0.055f) / 1.055f, 2.4f);
@@ -12,6 +14,15 @@ inline float linear_to_srgb(float x) {
   return 1.055f * std::pow(x, 1.0f / 2.4f) - 0.055f;
 }
 
+inline float gray_value(const cv::Vec3b& v) {
+  const float r = static_cast<float>(v[2]) * 0.299f;
+  const float g = static_cast<float>(v[1]) * 0.587f;
+  const float b = static_cast<float>(v[0]) * 0.114f;
+  return (r + g + b) / 255.0f;
+}
+
+}; // namespace
+
 namespace aznyan {
 
 /**