Color Pattern
Color Pattern
[Cueball holds up his smartphone in front of his laptop which stands in front of him on a desk. Megan is sitting in an armchair reading, facing away from Cueball. She is singing her reply, as indicated with four double musical notes around her two lines of text.] Cueball: I took a picture of my computer screen—why is the photo covered in these weird rainbow patterns? Megan: When a grid's misaligned with another behind Megan: That's a moiré...

The comic references moiré patterns in a parody of the song “ That's Amore ” made famous by Dean Martin in 1953 . (See trivia for pronunciation).
In mathematics, physics, and art, moiré patterns or moiré fringes are a kind of aliasing -- large scale interference patterns that can be produced when an opaque ruled pattern with transparent gaps is overlaid on another similar pattern. For the moiré interference pattern to appear, the two patterns must not be completely identical in that they must be displaced, rotated, etc., or have different but similar pitch. Moiré patterns appear in many different situations. In printing, the printed pattern of dots can negatively interfere with the image. In television and digital photography, a pattern on an object being photographed can interfere with the shape of the light sensors to generate unwanted artifacts .
In digital photography or videography, moiré patterns occur when the pattern of pixels on the image sensor are not 100% identically aligned with patterns on the subject being photographed.  Photographs of a digital screen taken with a digital camera often exhibit moiré patterns, since it is very difficult to align the camera sensor's grid with the screen's pixel grid perfectly.  This is the problem Cueball ran into, where the photo he just took of his computer screen is covered in weird rainbow patterns (the color patterns from the title).  It is possible to reduce this effect by changing the distance and angle between the camera and the screen.  There can also be bands of uneven brightness on digital photos or videos of electronic displays, those are caused by scan lines and are different from the moiré patterns described in this comic.
Megan responds to Cueball's complaint with a song that explains moiré patterns. Her song is a parody of the song That's Amore , where "Amore" means "love" in Italian. The pun is that "That's a Moiré" and "That's Amore" are phonetically quite similar . The title text continues the song with a second verse, again with musical notes indicating that it should be sung. More information on when moiré patterns occur is given here, indicating that the space between the grid lines should be small and the two grids should be almost identical, for the maximum moiré effect. This verse, however, could also work if a moiré was changed to amore , as two people squeezed tight together, and without much difference between them could lead to a romantic relationship.
Randall was not the first to spoof this song using "a moiré" instead of "Amore". His two verse version, two verses from the original song, and other prior versions can be found below .
It is the second time that Randall has changed the lyrics to "That’s Amore", although the first time, in 321: Thighs , he only changed eye to thigh in the original versions first verse.
It turns out that Randall was not the first to spot the possibility of changing the lyrics from "That’s Amore" to "That's a Moiré." Verses are shown below as follows: the lyrics first to the original song, then to Randall's song from this comic, and below that other songs (with citations).
The two first verse in the original song :
When a moon hits your eye like a big pizza pie That's amore
When the world seems to shine like you've had too much wine That's amore
The entire version of Megan's ( Randall's ) song is:
When a grid's misaligned with another behind That's a moiré...
When the spacing is tight And the difference is slight That's a moiré
A similar song based on the same pun was made by Craig Swanson in 1993 and can be found on his web comic Perspicuity in this comic: That's a Moiré . His song text was:
When new lines hit your eyes From two screens when they ply That's a Moire!
Jamie Zawinski and Michael Bayne wrote a similar verse for the Moiré screensaver they made in 1997 (search for that's to find it on the linked page):
When the lines on the screen Make more lines in between, That's a moiré!
[Cueball holds up his smartphone in front of his laptop which stands in front of him on a desk. Megan is sitting in an armchair reading, facing away from Cueball. She is singing her reply, as indicated with four double musical notes around her two lines of text.] Cueball: I took a picture of my computer screen—why is the photo covered in these weird rainbow patterns? Megan: When a grid's misaligned with another behind Megan: That's a moiré...
