can I omit there are

Question

I am having following construction,

The extraction of outline becomes very difficult if there are very short boundary edges where very few laser points reside.

I feel it is possible to omit the words "there are" from the above sentence. is that so?

Answer 1

You may not strike them, since that would leave your if clause incoherent.

Here's your structure (I've rewritten a little to make your phrases idiomatic):

[_{MAIN CLAUSE}
:   [_SUBJECT Extraction of the outline]
:   [_PREDICATE
:   :   [_VERB becomes]
:   :   [_COMPLEMENT very difficult]
:   ]
]
   [_{SUBORDINATE CLAUSE}
   :   [_SUBORDINATOR If]
   :   [_SUBJECT There]
   :   [_PREDICATE
   :   :   [_VERB are]
   :   :   [_COMPLEMENT very short boundary edges]
   :   :       [_ADJUNCT where very few laser points reside]
   :   ]
   ]

As you see, there are has a critical role in the sentence. It cannot be omitted.

Answer 2

No, 'there are' is required in the above sentence.

Also, you are missing a 'the' in the first phrase. 'The extraction of outline' should instead be:

The extraction of the outline

or

Extracting the outline

It might be a good idea to rewrite the sentence to something like:

Extracting the outline becomes much harder if there are very short boundary edges where only a few laser points reside.

This avoids using the word 'very' too much.

Just to let you know, the opening sentence could be:

I am having difficulty with constructing the following sentence:

or something similar. As it stands, it's not grammatically correct.