Often the number of horizontal pixels is implied from context and is omitted, as in the case of 720p and 1080p.
On November 13, 2008, larger formats were announced, including a proposed expansion of up to 28,000 horizontal pixels, for a 261 megapixel sensor.
In actual images, these extra pixels are often partly or entirely black, as only the center 704 horizontal pixels carry actual 4:3 or 16:9 image.
Using either character 221 or 222, each half of each truncated character cell can thus be treated as an individual pixel-making 160 horizontal pixels available per line.
Each column of pixels receives the spectrum of one horizontal pixel from the original image.
This is the reason we need the1920 horizontal pixels - each image (eye) will be squeezed to 960 pixels wide but will still be 1080 high.
There can be no more than 4 sprites on a single scanline; any additional sprites' horizontal pixels are dropped.
The standard display resolution of the NES is 256 horizontal pixels by 240 vertical pixels.
The Amiga had four basic resolutions, with either 320 or 640 horizontal pixels, and either 200 or 400 vertical.
Similarly, a sequence of three or more turned-off horizontal pixels would display as black.