You can't because the two format are radically diferent.
You have to import your document saved for example in photoshop in psd format
into a program like illustrator and redraw it with curves.
Vector shapes are a mathematic description of a figure, a square for example.
Pixel are little squares in wich you have bits that describes the number of colors in it.
BUT there is one program wich does it: Adobe streamline.
You can import you bitmap image into it and ask to transform it into a vector shape.
It works with very good with simple bitmap images.
If your bitmap is to complicated ( too much shapes, colors) it will turn it into a mess of
vector lines, unusable.
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