From 0d7b5ec5a0f7d3e8c9823c2dfda0f79a60cd20bf Mon Sep 17 00:00:00 2001
From: Dennis Eichhorn <spl1nes.com@googlemail.com>
Date: Sun, 14 Aug 2022 20:25:49 +0200
Subject: [PATCH] add rgbtoint

---
 Image/ImageUtils.h |  10 ++++
 Image/Kernel.h     | 117 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 127 insertions(+)
 create mode 100644 Image/Kernel.h

diff --git a/Image/ImageUtils.h b/Image/ImageUtils.h
index 7f78a74..f0e654c 100644
--- a/Image/ImageUtils.h
+++ b/Image/ImageUtils.h
@@ -34,6 +34,16 @@ namespace Image {
 
                 return lStar / 100.0;
             }
+
+            static inline
+            int rgbToInt(int r, int g, int b)
+            {
+                int rgb = r;
+                rgb     = (rgb << 8) + g;
+                rgb     = (rgb << 8) + b;
+
+                return rgb;
+            }
     };
 }
 
diff --git a/Image/Kernel.h b/Image/Kernel.h
new file mode 100644
index 0000000..c31576c
--- /dev/null
+++ b/Image/Kernel.h
@@ -0,0 +1,117 @@
+/**
+ * Karaka
+ *
+ * @package   Image
+ * @copyright Dennis Eichhorn
+ * @license   OMS License 1.0
+ * @version   1.0.0
+ * @link      https://karaka.app
+ */
+#ifndef IMAGE_KERNEL_H
+#define IMAGE_KERNEL_H
+
+#include <stdio.h>
+#include <opencv2/opencv.hpp>
+
+#include "ImageUtils.h"
+#include "../Utils/MathUtils.h"
+
+namespace Image {
+    const float KERNEL_RIDGE_1[3][3] = {
+        {0.0, -1.0, 0.0},
+        {-1.0, 4.0, -1.0},
+        {0.0, -1.0, 0.0}
+    };
+
+    const float KERNEL_RIDGE_2[3][3] = {
+        {-1.0, -1.0, -1.0},
+        {-1.0, 8.0, -1.0},
+        {-1.0, -1.0, -1.0}
+    };
+
+    const float KERNEL_SHARPEN[3][3] = {
+        {0.0, -1.0, 0.0},
+        {-1.0, 5.0, -1.0},
+        {0.0, -1.0, 0.0}
+    };
+
+    const float KERNEL_BOX_BLUR[3][3] = {
+        {1.0 / 9.0, 1.0 / 9.0, 1.0 / 9.0},
+        {1.0 / 9.0, 1.0 / 9.0, 1.0 / 9.0},
+        {1.0 / 9.0, 1.0 / 9.0, 1.0 / 9.0}
+    };
+
+    const float KERNEL_GAUSSUAN_BLUR_3[3][3] = {
+        {1.0 / 16.0, 2.0 / 16.0, 1.0 / 16.0},
+        {2.0 / 16.0, 4.0 / 16.0, 2.0 / 16.0},
+        {1.0 / 16.0, 2.0 / 16.0, 1.0 / 16.0}
+    };
+
+    const float KERNEL_EMBOSS[3][3] = {
+        {-2.0, -1.0, 0.0},
+        {-1.0, 1.0, 1.0},
+        {0.0, 1.0, 2.0}
+    };
+
+    const float KERNEL_UNSHARP_MASKING[5][5] = {
+        {-1.0 / 256.0,  -4.0 / 256.0, -6.0 / 256.0, -4.0 / 256.0, -1.0 / 256.0},
+        {-4.0 / 256.0,  -16.0 / 256.0, -24.0 / 256.0, -16.0 / 256.0, -4.0 / 256.0},
+        {-6.0 / 256.0,  -24.0 / 256.0, 476.0 / 256.0, -24.0 / 256.0, -6.0 / 256.0},
+        {-4.0 / 256.0,  -16.0 / 256.0, -24.0 / 256.0, -16.0 / 256.0, -4.0 / 256.0},
+        {-1.0 / 256.0,  -4.0 / 256.0, -6.0 / 256.0, -4.0 / 256.0, -1.0 / 256.0},
+    };
+
+    class Kernel {
+        private:
+
+        public:
+
+            /**
+             * @see https://en.wikipedia.org/wiki/Kernel_(image_processing)
+             * @see https://towardsdatascience.com/image-processing-with-python-blurring-and-sharpening-for-beginners-3bcebec0583a
+             * @see https://web.eecs.umich.edu/~jjcorso/t/598F14/files/lecture_0924_filtering.pdf
+             */
+            static
+            cv::Mat convolve(cv::Mat in, const float kernel[][3])
+            {
+                cv::Size dim = in.size();
+                cv::Mat out(in.size(), in.type());
+
+                int kernel_dimension = 3;
+
+                int kWidthRadius  = (unsigned int) kernel_dimension >> 1;
+                int kHeightRadius = (unsigned int) kernel_dimension >> 1;
+
+                int newPixel;
+                cv::Vec3b p;
+
+                // @todo: implement @see https://rosettacode.org/wiki/Image_convolution
+                // @todo: not working yet
+                for (int i = dim.width - 1; i >= 0; --i) {
+                    for (int j = dim.height - 1; j >= 0; --j) {
+                        newPixel = 0;
+
+                        for (int ki = kernel_dimension - 1; ki >= 0; --ki) {
+                            for (int kj = kernel_dimension - 1; kj >= 0; --kj) {
+                                p = in.at<cv::Vec3b>(
+                                    oms_min(oms_max(j + kj - kHeightRadius, 0), dim.height - 1),
+                                    oms_min(oms_max(i + ki - kWidthRadius, 0), dim.width - 1)
+                                );
+
+                                newPixel += kernel[ki][kj] * Image::ImageUtils::rgbToInt(p[2], p[1], p[0]);
+                            }
+                        }
+
+                        // bgr vs rgb
+                        out.at<cv::Vec3b>(j, i)[0] = newPixel & 255;
+                        out.at<cv::Vec3b>(j, i)[1] = (newPixel >> 8) & 255;
+                        out.at<cv::Vec3b>(j, i)[2] = (newPixel >> 16) & 255;
+                    }
+                }
+
+                return out;
+            }
+    };
+}
+
+#endif
\ No newline at end of file