ImageView iv = new ImageView(this);
LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
lp.setMargins(20, 0, 20, 0); // 마진 설정은 LayoutParams에서
layout.addView(iv, lp);
width, height 설정
iv.getLayoutParams().width = 100;
iv.getLayoutParams().height = 100;