c++ - Gamma Correction with pow -


i use gamma correction image. so, have pow every pixel intensity of source image g = 0.6. have problem cause destination image wrong. maybe have casting problem when take pixel source image. here code:

#include <opencv2/core.hpp> #include <opencv2/highgui/highgui.hpp> #include <iostream> #include <opencv2/imgproc/imgproc.hpp>  using namespace cv; using namespace std;   int main() {      mat src = imread("spine1.jpeg");       mat dst = mat(src.rows, src.cols, cv_8uc1);     cvtcolor(src, src, cv_8uc1);     dst = scalar(0);      (int x = 0; x < src.rows; x++) {         (int y = 0; y < src.cols; y++) {             int pixelvalue = (int)src.at<uchar>(x, y);              dst.at<uchar>(x, y) = pow(pixelvalue, 0.6);          }     }        namedwindow("input", cv_window_autosize);     namedwindow("output", cv_window_autosize);      imshow("input", src);     imshow("output", dst);      waitkey(0);     return 0; }

edit: change cvtcolor(src, src, cv_8uc1); in cvtcolor(src, src, color_bgr2gray);

the call cvtcolor wrong. should use:

cvtcolor(src, src, color_bgr2gray);

also, can make code simpler, , less error prone:

#include <opencv2/opencv.hpp>  int main() {     // load image grayscale     cv::mat1b src = cv::imread("path_to_img", cv::imread_grayscale);      // convert double "pow"     cv::mat1d dsrc;     src.convertto(dsrc, cv_64f);      // compute "pow"     cv::mat1d ddst;     cv::pow(dsrc, 0.6, ddst);      // convert uchar     cv::mat1b dst;     ddst.convertto(dst, cv_8u);      // show results     imshow("src", src);     imshow("dst", dst);     waitkey();      return 0; }

Comments

Post a Comment

Popular posts from this blog

asynchronous - C# WinSCP .NET assembly: How to upload multiple files asynchronously -

i using winscp .net assembly uploading files. want upload multiple files asynchronous way. have created method works single upload. public class uploadingdata { private sessionoptions _sessionoptions; private session _session; //connection etc private void onconnected() { foreach (var fileinfo in localfileslist) { var task = task.factory.startnew(() => uploadfilesasync(fileinfo)); } } private async task uploadfilesasync(string file) { string remotefilepath = _session.translatelocalpathtoremote(file, @"/", "/test_data_upload"); var uploading = _session.putfiles(file, remotefilepath, false); //when done await task.run(() => thread.sleep(1000)); } } please suggest me correct way. thanks you can use backgroundworker class this: string[] images = new string[50]; foreach (var path in images) { backgroundworker
Read more

aws api gateway - SerializationException in posting new Records via Dynamodb Proxy Service in API -

i getting "__type": "com.amazon.coral.service#serializationexception" as reply in postman & in test console in api gateway trying post record directly dynamodb using api proxy services.. referring aws article - https://aws.amazon.com/blogs/compute/using-amazon-api-gateway-as-a-proxy-for-dynamodb/ here's mapping { "tablename": "tablenamegoeshere", "item": { "id" : "$context.requestid" "eventname" : "$input.path('$.eventname')", "timestamp" : $input.path('$.timestamp'), "answers": "$util.parsejson($input.path('$.answers'))" } } update: did asked ... , worked if try add array of json objects gives me above same error - here's trying now. please - couldnt find on google well #set($inputroot = $input.path('$')) { "tablename": "answer", "item": {
Read more

asp.net - Problems sending emails from forum -

i have been redesigning site has message board, has been written guy looked after site. it has few problems , written in .asp , uses .mdb files database. you can see whole thing here . feel free post if helps, test thing have set using original files , new database. the basic problem when posts message, supposed email sent them, have posted it. when replies, originator supposed message, replier has been posted. i’d have thought @ point in process there should script/file in postmessage.asp? the postmessage.asp page below. <% option explicit %> <!-- #include virtual="common/adovbs.inc" --> <html> <head> <meta http-equiv="content-type" content="text/html; charset=windows-1252"> <meta name="generator" content="microsoft frontpage 4.0"> <meta name="progid" content="frontpage.editor.document"> <title>new page 2</title> <base target="_self"
Read more