Bits of color peek out through cracks in the dark shades of “La Miséreuse accroupie,” a 1902 painting by a young Pablo Picasso during his “Blue Period.”

That was not surprising. X-ray images taken a quarter-century ago had shown that Picasso had painted this work, known in English as “The Crouching Woman,” over another artist’s landscape.

Sandra Webster-Cook, a conservator of paintings at the Art Gallery of Ontario in Toronto, also observed brush strokes that seemed neither to reflect Picasso’s composition nor the underlying landscape.

“It was clear there was something else going on underneath,” she said.

Using tools originally developed for medicine, manufacturing and geology, researchers peered through the canvas without damaging it. They saw how Picasso had incorporated the contours of hills from the painter’s landscape into the curves of the woman’s back.

“Kind of a jazz riff back and forth,” said Marc Walton, a professor at Northwestern.

The analysis also uncovered Picasso’s repeated efforts to paint the woman’s right arm. He ultimately abandoned that part of the composition, covering it with a cloak.

“So this again is getting into the mind of the artist and understanding his creative process,” Walton said.