I just took a browse through my copy of SICP and see that the graphics are just diagrams. Crisp and clear diagrams. They are perfect for conversion to vector

I just took a browse through my copy of SICP and see that the graphics are just diagrams. Crisp and clear diagrams. They are perfect for conversion to vector format using Inkscape's "Trace Bitmap" feature. Doing this should take you less than a minute per diagram.