Skip to main content

How to make gaussian blur in SparkAR

 Gaussian blur is result of blurring an image by Gaussian function.




We need to use large kernel to make strong blur and this cause the high complexity. And that's why we should use multi-pass which is seperated into horizontal, vertical pass. It can reduce the complexity and make faster. In Spark AR there are many ways to make it. And I wanna introduce one of them using shader files (.sca). You can download it for free from the gumload link below. It is modulated to adjust horizontal, vertical strength easily. Hope this can help you.


Comments

Popular posts from this blog

OpenGL SL - Mosaic effect

Mosaic effect is similar to lowering the resolution of an image. Let's see example image. And full source code likes below. void mainImage( out vec4 fragColor, in vec2 fragCoord ){     // Normalized pixel coordinates (from 0 to 1)     vec2 uv = fragCoord/iResolution.xy;     if (uv.x > 0.7 && uv.y < 0.4 ){          //left bottoom small image         uv.x -= 0.6 ;         uv *= 2.0 ;         fragColor = texture (iChannel0, uv);         fragColor += vec4 ( 0.2 );         return ;     }     //mosaic effect     uv = uv * 30.0 ;     vec2 uv = floor (uv);     uv = uv/ 30.0 ;     fragColor = texture (iChannel0, uv); } The key function of mosaic effect is "floor" If you want to make it sharper, multiply uv by ...

OpenGL SL - Translate, roate, and scale

Translate, rotate and scale are most basic element of image effect. If you didn't understand how make effect at each pixel, please read again before post "Show Video and Image" . 1. Translate Translation means each pixel move parallel on the x, y-axis. In other words, if you want to translate 0.25 on the x-axis, a pixel should point to a distance of -0.25 from the original. Translate ex) void mainImage( out vec4 fragColor, in vec2 fragCoord ){     vec2 uv = fragCoord/iResolution.xy;     if (uv.x < 0.5 ){         // translate to x ( -0.25 )         uv.x += 0.25 ;     } else {         // translate to x ( +0.25 )         uv.x -= 0.25 ;     }     fragColor = texture (iChannel0, uv); } result) 2. Scale Scale also has a  similar concept to parallel translation. If you want to zoom in twice, each pixel s...

OpenCV : Image synthesis (ROI, Mask, Binary)

Today we will make Image synthesis by using ROI, Masking, binarization. The full code is like that. #include <iostream> #include "opencv2/opencv.hpp" using namespace std ; using namespace cv ; int main () { Mat me = imread( "./res/pic/mh.jpg" ); Mat animal = imread( "./res/pic/animal_head.png" ); Mat animalGray ; Mat mask_ani ; Mat mask_ani_inv ; imshow( "me origin" , me ); imshow( "animal" , animal ); cvtColor( animal , animalGray , CV_BGR2GRAY); // color to black and white threshold( animalGray , mask_ani , 10 , 255 , 0 ); // make binary bitwise_not( mask_ani , mask_ani_inv ); imshow( "mask ani inv" , mask_ani_inv ); imshow( "mask ani" , mask_ani ); Mat imgRoi ; imgRoi = me ( Rect ( 50 , 50 , animal . cols , animal . rows ) ) ; imshow( "imgRoi" , imgRoi ); Mat me_back ; Mat ani_for ; bitwise_and( animal ...