How to crochet this shape?

[Ettina]

How would I crochet the pattern in the middle of this flag?

[magiccrochetfan]

you could make an appliqué by using a pattern for a paisley and joining together 3 of them.  

if you want to do a non-textured pattern of color changes in plain stitches, there are programs where you can input an image and the program will turn it into a chart.  probably google 'chart generator from image' to find these.  

[Granny Square]

Another google option would be to google 'cross stitch grid (or chart, graph) generator'.  The chart generator I've used before seems to have changed hosts, try this http://www.theknittingsite.com/knitpro/

You'll want to chose a 1:1 ratio for crochet stitches, and decide on the closest number of stitches you want your pattern to cover.  You may have to clean up the resulting chart, there will be some grey pixels where the black and white edges meet.