In one of the many exchanges between lawyers and Judge Schroeder in the Kyle Rittenhouse trial, the degree to which pinching and zooming change cell phone images was addressed. Rittenhouse lawyer Mark Richards claimed it does. The district attorney Thomas Binger claimed there is no change.

Richards first claimed that an image prepared by the prosecutor changed pixels using AI and logarithms. If AI is defined as any “gee whiz” technology, he was right. But pinch and zoom was invented in 2007 by Steve Jobs and uses nothing that can be considered modern AI.

All nerds should laugh at the claim that “logarithms”  were used in the pinch and zoom.  Attorney Mark Richards obviously meant “algorithms”  To his credit, Richards confessed he knew little to nothing about the technology. So did Judge Bruce Schroeder.

In one exchange, DA Thomas Binger made a quick slip and called pixels “pickles.” He immediately corrected himself.

Judge Schroeder also slipped up on his terminology. He referred to a zoomed picture as being “amplified.” A more proper term would be “scaled” or “magnified.” Using an overhead projector,  images on a transparency  are amplified by using a brighter projector bulb.  

So who’s right on the main point? Does simple pinch and zoom change pixels? An article in Forbes says no. The devil, though, is in the details.

There are only so many pixels on your cell phone screen. As you pinch and zoom an image with more pixels than your cell phone, the manner the cell phone pixels are filled changes. The original pixels are not used. They are, rather,  interpolated. The only true image is one where each pixel has its own little square.

To illustrate, consider the image of “Lena,” often used to illustrate principles in image processing:

Zooming in on Lena’s right eye pixel by pixel gives the eye image shown below on the left. The interpolation using a lot of zoom is on the right:

I suspect, but don’t know, zooming to this level on an Apple cell phone is not possible. On my Android cell phone, endless zooming is not possible. The zoom eventually stops.

The bottom line is that zooming causes pixels to change. But the overall presentation of the image, though,  stays honest.

Here’s the discussion in the courtroom: