在目标 C 创建类似 instagram 的移轴滤镜
问题说明
我尝试在 iOS 中创建图像的移轴滤镜，例如 instagram 或 iDarkroom.
I trying to create a tilt-shift filter of the image like instagram or iDarkroom in iOS.
我提出的方法是对部分图像使用不同的高斯模糊级别.但我不知道如何控制区域以应用不同的高斯模糊级别，尤其是当用户可以通过旋转、缩放等改变效果区域时.
My proposed method is use different Gaussian Blur levels for the partial image. But I don't known how to control the area to apply different Gaussian Blur Levels, especially when User can change the effect area by rotate, scale, etc.
很抱歉我的演示很复杂，但很简单，我想为 iOS 创建一个 tilf-shift 工具，就像在 Instagram 中一样.
Sorry about my complex presentation but simply, I want to create a tilf-shift tool for iOS like in Instagram.
我搜索发现了这个强大的框架https://github.com/BradLarson/GPUImage，但是如果将这个巨大的框架包含到我的小应用程序中，这不是一个好的解决方案
I search and found this powerful framework https://github.com/BradLarson/GPUImage, but it's not good solution if include this huge framework to my tiny apps
正确答案
我找到了解决方案:
使用过滤器 GPUImageGaussianSelectiveBlurFilter 并在此代码上更改计算 distanceFromCenter:
Use filter GPUImageGaussianSelectiveBlurFilter and change computing distanceFromCenter on this code:
distanceFromCenter = abs((textureCoordinate2.x - excludeCirclePoint.x) *
aspectRatio*cos(angle) (textureCoordinate2.y-excludeCirclePoint.y)*sin(angle));
这篇好文章是转载于：学新通技术网
