QA Official

Normalization of Matlab Images

https://qaofficial.com/post/2019/04/02/68480-normalization-of-matlab-images.html 2019-04-02
1, why normalization? 1. Basically, the idea of normalization is to find a set of parameters by using the invariant moments of the image so that it can eliminate the influence of other transformation functions on image transformation.In other words, it is converted to a unique standard form to resist affine transformation. Image normalization enables images to resist attacks of geometric transformation. It can find those invariants in images, thus knowing that these images are originally one or a series.

OpenCV Learning Notes (1)-Resize Function Realizes Image Size Normalization

https://qaofficial.com/post/2019/04/02/68464-opencv-learning-notes-1-resize-function-realizes-image-size-normalization.html 2019-04-02
in the process of image processing, sometimes need to adjust the image to the same size, easy to process, then need to use image resize () original function void resize(InputArray src, OutputArray dst, Size dsize, double fx=0, double fy=0, int interpolation=INTER_LINEAR ) The first two parameters are input and output images respectively.Dsize indicates the size of the output image, if 0, then dsize和fx

Operating System

https://qaofficial.com/post/2019/04/02/68399-operating-system.html 2019-04-02
Operating System 中间商, 翻译官 Application --> Operation System --> Hardware command line 快速回到行首: ctrl + A 快速回到行尾: ctrl + E action 向上: 为 应用程序 提供支持 向下: 控制/ 管理/ 调度 硬件 truncation 截断: 从文件

Three Ways for Front End to Send get and post Requests

https://qaofficial.com/post/2019/04/02/68540-three-ways-for-front-end-to-send-get-and-post-requests.html 2019-04-02
1. Send request with XMLHttpRequest object (1)get request var xmlhttp; if (window.XMLHttpRequest) {// code for IE7+, Firefox, Chrome, Opera, Safari xmlhttp=new XMLHttpRequest(); } else {// code for IE6, IE5 xmlhttp=new ActiveXObject("Microsoft.XMLHTTP"); } xmlhttp.onreadystatechange=function() { if (xmlhttp.readyState==4 && xmlhttp.status==200) { document.getElementById("div").innerHTML=xmlhttp.responseText; } } xmlhttp.open("GET","forwifestudy/testforget.php?info=123",true); xmlhttp.send(); Note: Any browser except IE5 and IE6 can create an XHR object. In IE, XHR is implemented as an ActiveX object. In IE, the object is

Understanding and Use of Python Multithreading (1) Understanding of join () Function in Threading

https://qaofficial.com/post/2019/04/02/68387-understanding-and-use-of-python-multithreading-1-understanding-of-join-function-in-threading.html 2019-04-02
1. The concept of multithreading Multithreading is similar to executing multiple different programs at the same time. Multithreading has the following advantages: Using threads can put tasks in programs that occupy a long time into the background for processing. The user interface can be more attractive. For example, if the user clicks a button to trigger the processing of certain events, a progress bar can pop up to show the

ajax Cross-Domain Setting of http header in jQuery

https://qaofficial.com/post/2019/04/02/68534-ajax-cross-domain-setting-of-http-header-in-jquery.html 2019-04-02
This article discusses ajax requests from the following situations: No cross-domain, set http header header header (e.g. authorization);Cross-domain, no http header header set;Cross-domain, set http header header header;In addition, php sends http requests and sets http Header header; Jsonp Personal Understanding, Reference1. ajax request, no cross-domain, set http Header header $.ajax({ type: "post", url:"http://abc.cc/qrcode3/index.php/home/index/testpost", dataType: "json" data: {"key":"value"}, // headers : {'Authorization':'Basic bmVvd2F5Oe4lb3dheQ=='},

argv and environment variables under Linux

https://qaofficial.com/post/2019/04/02/68413-argv-and-environment-variables-under-linux.html 2019-04-02
Look at the code first #include <stdio.h> #include <stdlib.h> int main(int argc, char *argv[]) { extern char **environ; int i=0; while( argv[i] != NULL ) { printf("%p:%s\n", argv[i], argv[i]); i++; } printf("%p:%s\n\n", argv[i], argv[i]); i=0; char **ptr = argv + argc + 1; /* points to environment, in Un*x */ if ( ptr == environ ) { printf("========== ptr equals environ ==========\n\n"); } while( environ[i] != NULL ) { printf("%p:%s\n",

jquerajax cross-domain POST request

https://qaofficial.com/post/2019/04/02/68539-jquerajax-cross-domain-post-request.html 2019-04-02
A cross-domain post request was encountered in the project and a pit was encountered below IE10. CORS is used across domains 1, front-end script <script> function tests(){ //请求类型 为了满足IE8,IE9通过cors跨域请求 var contentType ="application/x-www-form-urlencoded; charset=utf-8"; //var contentType ="text/plain; charset=utf-8"; //contentType ="application/json; charset=utf-8", /* if(window.XDomainRequest){ //for IE8,IE9 contentType

popular science of Android multitasking mechanism (suddenly enlightened series)

https://qaofficial.com/post/2019/04/02/68391-popular-science-of-android-multitasking-mechanism-suddenly-enlightened-series.html 2019-04-02
Why don't you need to clear the memory?Back then, the habit of clearing memory has a long history.Before Android was born, when we used Windows , we were always eager to turn off all unused processes, so that we would not " occupy memory", CPU and computer.(Most " security software" is famous for helping users clean up memory and garbage in Windows .) This is the historical reason for cleaning up memory.

threading module in Python

https://qaofficial.com/post/2019/04/02/68389-threading-module-in-python.html 2019-04-02
threading- higher level thread interface source code: Lib/threading.py This module builds a higher level thread interface on top of the lower level thread module.See also mutex and Queue modules. This dummy_threading module is applicable to situations where threading cannot be used due to the absence of thread. note: starting with Python 2.6, this module provides PEP 8-compliant aliases and attributes to replace camelCase's Java-inspired thread API name.This updated API is compatible with the apis of the multiprocessing module.