从设备的file.uri动态创建低分辨率缩略图，用于cordova项目中的图库图像(Dynamically creating low resolution thumbnails from a device's file.uri for gallery images in a cordova project)

 我可能在这里不合适但我想在我尝试解决之前找出是否确实有这个问题的解决方案。 
 
 我在iOS上使用cordova并访问设备的图像库，获取照片的file.uri（根据phongap文档最少的内存饥饿方式），然后将其渲染为页面上大约50px x 50px的图像。 
 
 我遇到的问题是，一旦我将4张或更多张照片加载到页面上，性能开始受到影响，对其他表单元素的关注变得缓慢，并且有点“不稳定”。 我认为这与我显然在一个小盒子中渲染高分辨率图像这一事实有关，当你在一个页面上有多个高分辨率图像时，你会对设备的资源造成严重压力。 这是在iPhone 5上，我认为性能会更糟，仍然是4s和4。 
 
 有没有办法以编程方式创建图像的“低分辨率”版本，然后在我的页面上使用这些低分辨率图像？ 从理论上讲，我可以访问图像及其位置，因此，为了提高性能，我是否可以动态转换/压缩/缩小这些图像，然后在完成实际图像文件的上传后丢弃这些缩略图/临时图像？ 

I may be off the mark here but I wanted to find out if there actually is a solution to this problem before I try and solve it. 
 
I'm using cordova on iOS and accessing the device's image gallery, fetching a photo's file.uri (the least memory hungry way according to phongap docs) and then rendering this into a roughly 50px x 50px image on the page. 
 
The problem I've run into is that once I have loaded 4 or more photos onto the page, the performance starts to suffer, focus on other form elements becomes slow, and somewhat 'jerky'. I believe that this has to do with the fact that I am obviously rendering a high resolution image in a tiny box and when you have multiple high res images on one page you put a serious strain on the device's resources. This is on an iPhone 5, I would imagine the performance to be worse still on a 4s and 4.
 
Is there a way to programatically create 'low res' versions of the image(s) and then use these low res images on my page? In theory I have access to the image and its location, so can I not convert/compress/downscale these on the fly for the purpose of improving performance and then ditch these thumbnails/temp images once any upload of the actual image files is complete? 

原文：https://stackoverflow.com/questions/21184070