Resolución: 

Zoom

t = 16 (slider from 1 to 16, step 1)
r = 26 (slider from 1 to 26, step 1)
A: Corner[4.0] - (0.0, 12.0 - 3.0 * (16.0 - t) / 4.0)
B: A + (t, 0.0)
rx = If(r ≟ 26.0, 800.0, round(400.0 / (26.0 - r)))
ry = If(r ≟ 26.0, 600.0, round(300.0 / (26.0 - r)))
texto5: "" + rx + " x " + ry + " (píxeles)"
texto2: "Peso: " + (round(rx * ry * 300.0 / 1024.0) / 100.0) + " kB" + "
(sin comprimir)"