I wrote:
The next stage is to detect bending and to measure the degree of bending.For this purpose, first, a region in the image that includes the top edge is identified. Then, a curve is fitted through the edge pixels in the region.
In the sentence above where should I put first? Did I use commas correctly?
should I say ...top edge is first identified?
I myself prefer to use first, or then in the beginning of sentence to show the order. Is it a good practice?