ImageConsumers not working unless class variable about gpuimage2

[BradLarson]

The way that the memory management architecture works is that the outputs are the roots for the memory graph, with strong links flowing backwards from them to their inputs. The original GPUImage was the opposite of this, which led to many bugs where people created image inputs and didn't hang on to them, which could lead to crashes or bizarre output.

The problem with PictureOutputs is in the case above, where you're setting up a fire-and-forget block callback and throwing away the PictureOutput. I need to make the block retain its host PictureOutput for as long as it takes the block to be called once, then get rid of it to break the retain cycle. I'm working on a way to do that that hopefully won't leak.

In the meantime, I recommend setting up instance variables for outputs you wish to survive past the immediate scope.