小编hen*_*oem的帖子

我试图从静止图像中获取角点GPUImageHarrisCornerDetectionFilter.

我查看了项目中的示例代码,我查看了文档,我看过这篇文章大致相同的事情: 现有UIImage上的GPUImage Harris Corner Detection提供黑屏输出

但我无法让它发挥作用 - 我很难理解这应该如何与静止图像一起使用.

我现在所拥有的是:

func harrisCorners() -> [CGPoint] {
    var points = [CGPoint]()

    let stillImageSource: GPUImagePicture = GPUImagePicture(image: self.image)
    let filter = GPUImageHarrisCornerDetectionFilter()

    filter.cornersDetectedBlock = { (cornerArray:UnsafeMutablePointer<GLfloat>, cornersDetected:UInt, frameTime:CMTime) in
        for index in 0..<Int(cornersDetected) {
            points.append(CGPoint(x:CGFloat(cornerArray[index * 2]), y:CGFloat(cornerArray[(index * 2) + 1])))
        }
    }

    filter.forceProcessingAtSize(self.image.size)
    stillImageSource.addTarget(filter)
    stillImageSource.processImage()

    return points
}

此函数总是返回,[]因此它显然不起作用.

一个有趣的细节 - 我从GPUImage示例中编译了FilterShowcaseSwift项目,并且过滤器无法找到非常清晰的角落,就像在黑色背景上的一张纸上一样.

我正在尝试创建一个正则表达式来匹配一个持有MySQL时间戳格式的日期的字符串,例如"2012-07-16 02:04:33".

它并不像听起来那么容易,例如你不应该在2月30日结束.

我知道有更简单的方法可以做到这一点,但我依赖于能够传递字符串和正则表达式来评估该字符串.

我很乐意提出任何建议.

djangoproject.com上的Django教程给出了这样的模型:

import datetime
from django.utils import timezone
from django.db import models

class Poll(models.Model):
    question = models.CharField(max_length = 200)
    pub_date = models.DateTimeField('date published')

    def __unicode__(self):
        return self.question

    def was_published_recently(self):
        now = timezone.now()
        return now - datetime.timedelta(days = 1) <= self.pub_date < now

    was_published_recently.admin_order_field = 'pub_date'
    was_published_recently.boolean = True
    was_published_recently.short_description = 'Published recently?'

class Choice(models.Model):
    poll = models.ForeignKey(Poll)
    choice_text = models.CharField(max_length = 200)
    votes = models.IntegerField(default = 0)

    def __unicode__(self):
        return self.choice_text

Choice使用ForeignKey,这是一种多对一的关系,所以我应该能够使用一个选择进行多个轮询.如果我尝试从夹具中加载它,如下所示:

[
    {
        "model": "polls.Poll",
        "pk": 3,
        "fields": { …

我正在使用Blueimp fileupload()将图像文件发布到django-tastypie API.

在上传文件时,以下代码可正常工作:

        $("#image").fileupload({
            dataType: 'json',
            start: function() {
                console.log("start fileupload");
            },
            progress: function(e, data) {
                console.log(data.loaded + " " + data.total);
            },
            beforeSend: function(xhr, settings) {
                xhr.setRequestHeader("X-CSRFToken", $.cookie('csrftoken'));
            },
            done: function(e, data) {
                console.log("done uploading file.");
            }                   
        });

        $("#image").bind('fileuploadfinished', function (e, data) {
            console.log("fileuploadfinished");
        });

但是,done永远不会调用回调.我尝试绑定fileuploadfinished,也从未调用过.

start并且progress都按预期调用.

beforeSend没有文档,但django-tastypie需要SessionAuthentication- 删除它不会改变它done,fileuploadfinished也永远不会被调用.

当多个 Markdown 文件中的任何一个发生更改时，我正在尝试使用 Makefile 来编译 PDF：

# Compile report

source := draft
output := dist
sources := $(wildcard $(source)/*.md)
objects := $(patsubst %.md,%.pdf,$(subst$(source),$(output),$(sources)))
all: $(objects)

report-print.md: $(source)/%.md
    cat draft/*.md | pandoc \
        --variable geometry:a4paper \
        --number-sections \ 
        --toc \
        --f markdown \
        -s \
        -o dist/report-print.pdf \ 

.PHONY : clean

clean:
    rm -f $(output)/*.pdf

我收到一个错误：

make: *** No rule to make target `dist/01-title.pdf', needed by `all'.  Stop.

该文件draft/01-title.md是源文件之一。

我试图在UIView中显示相机的输入.后来我需要能够分析视频帧,所以我需要使用AVFoundation这样做,据我所知.

到目前为止我所拥有的:

import UIKit
import AVFoundation

class ViewController: UIViewController {

    @IBOutlet weak var camView: UIView!

    var captureSession:AVCaptureSession?
    var videoPreviewLayer:AVCaptureVideoPreviewLayer?
    var videoCaptureDevice: AVCaptureDevice?
    var input: AnyObject?

    override func viewDidLoad() {
        super.viewDidLoad()

        videoCaptureDevice = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
        do {
            input = try AVCaptureDeviceInput(device: videoCaptureDevice)
        } catch {
            print("video device error")
        }
        captureSession = AVCaptureSession()
        captureSession?.addInput(input as! AVCaptureInput)
        videoPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
        videoPreviewLayer?.videoGravity = AVLayerVideoGravityResizeAspectFill
        videoPreviewLayer?.frame = camView.layer.bounds
        captureSession?.startRunning()
    }
}

这camView是可见的,但它没有显示任何内容.

该应用程序要求获得首次使用相机的许可,并已获得该许可.

设置断点和检查captureSession,videoPreviewLayer,videoCaptureDevice并input证实他们都被设定.