Editing Image resolution (section)

===Pixel count{{anchor|Pixel resolution}}===<!-- This section is linked from [[PlayStation Eye]] -->
The term ''resolution'' is often considered equivalent to [[pixel]] count in [[digital imaging]], though international standards in the [[digital camera]] field specify it should instead be called "Number of Total Pixels" in relation to image sensors, and as "Number of Recorded Pixels" for what is fully captured. Hence, [[CIPA DCG-001]] calls for notation such as "Number of Recorded Pixels 1000 × 1500".<ref>[http://www.cipa.jp/std/documents/e/DCG-001_E.pdf] {{Webarchive|url=https://web.archive.org/web/20170202125644/http://www.cipa.jp/std/documents/e/DCG-001_E.pdf|date=2017-02-02}} Guideline for Noting Digital Camera Specifications in Catalogs. "The term 'Resolution' shall not be used for the number of recorded pixels"</ref><ref>[https://web.archive.org/web/20051126202022/http://webstore.ansi.org/ansidocstore/product.asp?sku=ANSI%2FI3A+IT10%2E7000%2D2004 ANSI/I3A IT10.7000–2004] Photography – Digital Still Cameras – Guidelines for Reporting Pixel-Related Specifications</ref> According to the same standards, the "Number of Effective Pixels" that an [[image sensor]] or [[digital camera]] has is the count of [[pixel]] sensors that contribute to the final image (including pixels not in said image but nevertheless support the image filtering process), as opposed to the number of ''total pixels'', which includes unused or light-shielded pixels around the edges.

An image of N pixels height by M pixels wide can have any resolution less than N lines per picture height, or N TV lines. But when the pixel counts are referred to as "resolution", the convention is to describe the ''pixel resolution'' with the set of two positive [[integer]] numbers, where the first number is the number of pixel columns (width) and the second is the number of pixel rows (height), for example as ''7680 × 6876''. Another popular convention is to cite resolution as the total number of pixels in the image, typically given as number of [[megapixel]]s, which can be calculated by multiplying pixel columns by pixel rows and dividing by one million. Other conventions include describing pixels per length unit or pixels per area unit, such as [[pixels per inch]] or per square inch. None of these ''pixel resolutions'' are true resolutions{{Clarify|reason=|date=August 2017}}, but they are widely referred to as such; they serve as [[upper bound]]s on image resolution.

Below is an illustration of how the same image might appear at different pixel resolutions, if the pixels were poorly rendered as sharp squares (normally, a smooth image reconstruction from pixels would be preferred, but for illustration of pixels, the sharp squares make the point better).

[[File:Resolution illustration.png]]

An image that is 2048 pixels in width and 1536 pixels in height has a total of 2048×1536 = 3,145,728 pixels or 3.1 megapixels.  One could refer to it as 2048 by 1536 or a 3.1-megapixel image. The image would be a very low quality image (72ppi) if printed at about 28.5 inches wide, but a very good quality (300ppi) image if printed at about 7 inches wide.

The number of photodiodes in a color [[digital camera]] image sensor is often a multiple of the number of pixels in the image it produces, because information from an array of color [[image sensors]] is used to reconstruct the color of a single pixel. The image has to be interpolated or [[demosaic]]ed to produce all three colors for each output pixel.