Step 1: Get Images
Step 2: Photoshop: Isolate Figures
Step 3: Photoshop: Merge and Generate Mask
Create a new layer and select the inverse (Select>>Inverse). Then use the paint bucket tool to fill the selected area with a solid color. Delete the background layer and save as a png (to preserve transparancy). I've attached my png file (fig 5).
Step 4: Illustrator
Step 5: Laser Cut
Size the images according to the size of tissue paper you have (mine was ~20x26") and send to laser cutter.