Whether in which is correct depends on what the sentence means, which is not very clear.
What does the relative clause modify? Is it
* An approach to [not for] object recognition, or
* shape knowledge?
If it modifies approach, then in which a set of attributes ... are introduced might be paraphrased:
In [the course of developing/describing] this approach ... I introduce a [new] set of attributes.
That would be reasonably idiomatic. But if it modifies shape knowledge, introduce would imply something you are adding to existing 'shape knowledge', and you should use a different idiom:
... shape knowledge into which I introduce a [new] set of attributes.