pixel

But one area in which there has been no improvement was in the use of square pixels. This use of square pixels that I started resulted from my lack of awareness of a method used 1500 years previously by the mosaic artists in Ravenna when they chose tesserae carefully by shape and color to best represent their mosaic images.

Since the first digital image was of a newborn infant in 1957, I include here two color images of the same 53 year old today using both conventional square pixels in Fig.

1 shows a conventional scanned color image in which all of the red, green, and blue components are square pixels. Fig.

Thus a pair of pixels requires 19 bits compared to the 16 required for a pair of square pixels. Thus the greater accuracy here is achieved at the cost of an additional 18.75% storage requirement.

In the examples below we show that the usual assumption that increased precision is accomplished with higher resolution of square pixel images does not necessarily result in the increased accuracy that can be achieved with the use of variable shape pixels each chosen to best represent the image being displayed.

The original square pixel image is analyzed through masks of size 6 x 6 pixels.