小编kav*_*kav的帖子

我有以下图片:

我想使用cv::inRange方法和HSV颜色空间检测红色矩形.

int H_MIN = 0;
int H_MAX = 10;
int S_MIN = 70; 
int S_MAX = 255;
int V_MIN = 50;
int V_MAX = 255;

cv::cvtColor( input, imageHSV, cv::COLOR_BGR2HSV );

cv::inRange( imageHSV, cv::Scalar( H_MIN, S_MIN, V_MIN ), cv::Scalar( H_MAX, S_MAX, V_MAX ), imgThreshold0 );

我已经创建了动态轨迹栏以便更改HSV的值,但是我无法获得所需的结果.

是否有关于使用最佳值(也许是过滤器)的建议？

我的JSON是:

[
   {
      "distance":32,
      "stationCode":"MIG",
      "name":"Midghat",
      "platforms":"2"
   },
   {
      "distance":32,
      "stationCode":"MIG",
      "name":"Midghat",
      "platforms":"2"
   },
   {
      "distance":69,
      "stationCode":"MDDP",
      "name":"Mandideep",
      "platforms":"2"
   },
   {
      "distance":69,
      "stationCode":"MDDP",
      "name":"Mandideep",
      "platforms":"2"
   },
   {
      "distance":18,
      "stationCode":"HBD",
      "name":"Hoshangabad",
      "platforms":"2"
   },
   {
      "distance":18,
      "stationCode":"HBD",
      "name":"Hoshangabad",
      "platforms":"2"
   },
   {
      "distance":37,
      "stationCode":"CHQ",
      "name":"Choka",
      "platforms":"2"
   },
   {
      "distance":37,
      "stationCode":"CHQ",
      "name":"Choka",
      "platforms":"2"
   },
   {
      "distance":85,
      "stationCode":"HBJ",
      "name":"Habibganj",
      "platforms":"5"
   },
   {
      "distance":85,
      "stationCode":"HBJ",
      "name":"Habibganj",
      "platforms":"5"
   },
   {
      "distance":0,
      "stationCode":"ET",
      "name":"ItarsiJn",
      "platforms":"28"
   },
   {
      "distance":8,
      "stationCode":"PRKD",
      "name":"Powerkheda",
      "platforms":"2"
   },
   {
      "distance":8,
      "stationCode":"PRKD",
      "name":"Powerkheda",
      "platforms":"2"
   }, …

我正在尝试将canvas的drawImage方法与视频源一起使用,但它在使用Chrome浏览器测试的Android 4.4.2中无效.

这是我的代码:

$(function() {

    var canvas = document.getElementById('canvas');
    var ctx = canvas.getContext('2d');
    var video = document.getElementById('video');

    var videoWidth; 
    var videoHeight;    

    var paused = false;

    canvas.addEventListener('click', function() {   
        if (paused) {
            video.play(); 
        } else {
            video.pause();
        }
        paused = !paused;
    });

    video.addEventListener("loadedmetadata", function() {
        videoWidth = this.videoWidth || this.width;
        videoHeight = this.videoHeight || this.height;
        canvas.width = videoWidth;
        canvas.height = videoHeight;
    }, false);

    video.addEventListener('play', function() {
        var $this = this; // cache
        (function loop() {
            if ( ! $this.paused …

我正在尝试从中选择一组选项中的第一个值 <mat-autocomplete ...>

export class ExampleComponent implements OnInit, AfterViewInit {

@ViewChildren('auto') matAutocomplete: QueryList<any>;

constructor(private cdr: ChangeDetectorRef) { }

ngAfterViewInit() {
    this.foundItemsList.changes.subscribe(options => {
        // ---> This simply works!
        setTimeout(() => this.matAutocomplete.first._keyManager.setFirstItemActive(), 0);

        // ---> This doesn't works?! No error shown, it just seems that the above function isn't called at all. 
        this.matAutocomplete.first._keyManager.setFirstItemActive()
        this.cdr.detectChanges();
    });
}

https://github.com/angular/material2/blob/master/src/lib/autocomplete/autocomplete.ts

AFAIK,detectChanges检查当前组件及其所有子组件的变化检测器是什么,对吗？但似乎它在上面的场景中不起作用.

我有以下数据库(简化):

CREATE TABLE `tracking` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `manufacture` varchar(100) NOT NULL,
  `date_last_activity` datetime NOT NULL,
  `date_created` datetime NOT NULL,
  `date_updated` datetime NOT NULL,
  PRIMARY KEY (`id`),
  KEY `manufacture` (`manufacture`),
  KEY `manufacture_date_last_activity` (`manufacture`, `date_last_activity`),
  KEY `date_last_activity` (`date_last_activity`),
) ENGINE=InnoDB AUTO_INCREMENT=401353 DEFAULT CHARSET=utf8

CREATE TABLE `tracking_items` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `tracking_id` int(11) NOT NULL,
  `tracking_object_id` varchar(100) NOT NULL,
  `tracking_type` int(11) NOT NULL COMMENT 'Its used to specify the type of each item, e.g. car, bike, etc',
  `date_created` …

在Symfony Progress Bar 文档中，有一个超酷进度条的示例图像。不幸的是，看起来文档的其余部分没有解释如何获得这样的结果。这是图片，以防您错过：

我怎么才能得到它？

我试图获得标签的宽度和高度,我使用以下标记:

<div class="masked" id="video_container">
    <video id="video" loop="loop" muted="muted" tabindex="0" style="width: 100%; height: 100%;">
        <source src="..." type="..."</source>
        <source src="..." type="..."</source>
    </video>
</div>

关键部分是宽度和高度属性都设置为100%,当窗口改变时,视频的宽高比被保存,但我无法得到它的实际宽度和高度.

我尝试使用offsetWidth和offsetHeight属性获取值,但它们返回视频的实际大小.

编辑:

这是为我工作的代码段:

var videoActualWidth = video.getBoundingClientRect().width;
var videoActualHeight = video.getBoundingClientRect().height;

var aspect = videoActualWidth / videoActualHeight;

if (w / h > aspect) {
    video.setAttribute("style", "height: 100%");
} else {
    video.setAttribute("style", "width: 100%");
}

谢谢!