Warren Moore

to explain the situation. Im getting some source image at a 320 x 480 resolution and apply the sobel filter for now. But the result in my mtk view is a tiny rectangle at the top right because of this resolution and so I want to resize the texture before applying the sober filter.

Oh, you want to upsample from the source first? In that case, MPSImageScale up to the desired size (yes, you have to compute the dest size manually); at worst use Lanczos (you probably don’t need it); then feed that to your Sobel.

Sorry if this is obtuse; I really should write a new article about all of this

Ah I didn't even know sobel is only applied to 1:1 aspect images, I'm using it on something 320 x 240. But yes that's exactly what I'm trying to do. So the thing to do is have one intermediate texture of the same size as my drawable?

Sorry, I meant Sobel’s input dimensions are the same as the output, not to imply the aspect ratio has to be 1:1. But yes, it sounds like you want to allocate an intermediate texture that is the size expected as the output of your upsampling kernel.

Thanks a lot! I'm gonna see if I can get it to work!

Let me know how it goes!

Hm still can't get the resizing to work. Are there any examples of attaching the ScaleTransform to the filter you know of? I couldn't find any, even in the documentation.