du20150401 2016-01-22 05:23
浏览 260
已采纳

php - 如何使用imagick或其他库找到图像中边缘的坐标?

given an image composed of a plain black field with a single white rectangle inside it somewhere, how can i extract the coordinates of the rectangle ? i've googled and googled and found numerous articles on edge detection using hough lines, convolution, morphology, etc., but all of these actually edge the image or convert it in some way. i don't want to change the image, all i want to do is find where the edges are.

obviously, i could simply iterate over the entire width+height of the image and look at the pixel colours (as some posts suggest), but that seems horribly inefficient. is there no built-in algorithm ? it seems like this must be part of imagick somewhere, otherwise how could it actually find and draw the edges of internal images ? but i'm having trouble finding out how to get at it.

  • 写回答

2条回答 默认 最新

  • douxueke5653 2016-01-22 21:45
    关注
    $base = new Imagick(realpath('./trim.png'));
    $base->trimImage(0);
    // get the new image size
    $geometry = $base->getImageGeometry();
    // Retrieve the trim info
    $pageInfo = $base->getImagePage();
    

    A similar example is on the manual page: http://php.net/manual/en/imagick.trimimage.php#111332

    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论
查看更多回答(1条)

报告相同问题?

悬赏问题

  • ¥15 矩阵加法的规则是两个矩阵中对应位置的数的绝对值进行加和
  • ¥15 活动选择题。最多可以参加几个项目?
  • ¥15 飞机曲面部件如机翼,壁板等具体的孔位模型
  • ¥15 vs2019中数据导出问题
  • ¥20 云服务Linux系统TCP-MSS值修改?
  • ¥20 关于#单片机#的问题:项目:使用模拟iic与ov2640通讯环境:F407问题:读取的ID号总是0xff,自己调了调发现在读从机数据时,SDA线上并未有信号变化(语言-c语言)
  • ¥20 怎么在stm32门禁成品上增加查询记录功能
  • ¥15 Source insight编写代码后使用CCS5.2版本import之后,代码跳到注释行里面
  • ¥50 NT4.0系统 STOP:0X0000007B
  • ¥15 想问一下stata17中这段代码哪里有问题呀