ImageMagick Transform - "Affine"

In addition to drastically increasing image size, Affine produces a transparent BG. However, because I output as jpg, the BGs in these samples are white-- output as gif to preserve the transparency.

Original 151x180
@ 1.2,2.3,2.2,1.1,2.1,3.2 577x545	@ 3.2,2.3,2.2,1.1,2.1,1.2 879x545
@ 1.2,3.2,2.1,1.2,2.3,2.1 559x699	@ 2.2,1.2,1.1,1.1,1.3,2.1 530x379
@ 2.2,2.3,1.1,1.1,2.3,2.2 530x545	@ 3.2,1.1,1.2,1.2,1.1,3.2 699x382
@ 1.5,2.1,1.1,1.1,2.1,4.5 425x515	@ 4.5,2.1,1.1,1.1,2.1,1.5 878x515
@ 1.2,3.5,1.1,1.1,1.1,1.2 379x727	@ 1.2,1.1,3.5,1.1,1.1,1.2 811x364
@ 1.2,1.1,1.1,3.5,1.1,1.2 379x796	@ 3.2,1.1,3.5,3.5,1.1,1.2 1113x796