Image resolution
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Image resolution is the level of detail of an image. The term applies to digital images, film images, and other types of images. "Higher resolution" means more image detail. Image resolution can be measured in various ways. Resolution quantifies how close lines can be to each other and still be visibly resolved. Resolution units can be tied to physical sizes (e.g. lines per mm, lines per inch), to the overall size of a picture (lines per picture height, also known simply as lines, TV lines, or TVL), or to angular subtense. Instead of single lines, line pairs are often used, composed of a dark line and an adjacent light line; for example, a resolution of 10 lines per millimeter means 5 dark lines alternating with 5 light lines, or 5 line pairs per millimeter (5 LP/mm). Photographic lens are most often quoted in line pairs per millimeter.
Types
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The resolution of digital cameras can be described in many different ways.
Pixel count
The term resolution is often considered equivalent to
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
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).
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
Spatial resolution
The terms blurriness and sharpness are used for digital images but other descriptors are used to reference the hardware capturing and displaying the images.
Spatial resolution in radiology is the ability of the imaging modality to differentiate two objects. Low spatial resolution techniques will be unable to differentiate between two objects that are relatively close together.
The measure of how closely lines can be resolved in an image is called spatial resolution, and it depends on properties of the system creating the image, not just the pixel resolution in
The spatial resolution of consumer displays ranges from 50 to 800 pixel lines per inch. With scanners, optical resolution is sometimes used to distinguish spatial resolution from the number of pixels per inch.
In
In
In Stereoscopic 3D images, spatial resolution could be defined as the spatial information recorded or captured by two viewpoints of a stereo camera (left and right camera).
Spectral resolution
Pixel encoding limits the information stored in a digital image, and the term color profile is used for digital images but other descriptors are used to reference the hardware capturing and displaying the images.
Spectral resolution is the ability to resolve spectral features and bands into their separate components.
Temporal resolution
Temporal resolution (TR) is the precision of a measurement with respect to time.
The Heisenberg uncertainty principle describes the fundamental limit on the maximum spatial resolution of information about a particle's coordinates imposed by the measurement or existence of information regarding its momentum to any degree of precision.
This fundamental limitation can, in turn, be a factor in the maximum imaging resolution at subatomic scales, as can be encountered using scanning electron microscopes.
Radiometric resolution
Resolution in various media
This is a list of traditional, analogue horizontal resolutions for various media. The list only includes popular formats, not rare formats, and all values are approximate, because the actual quality can vary machine-to-machine or tape-to-tape. For ease-of-comparison, all values are for the NTSC system. (For PAL systems, replace 480 with 576.) Analog formats usually had less chroma resolution.
- Analogue and early digital[3]
Many cameras and displays offset the color components relative to each other or mix up temporal with spatial resolution:
-
digital camera (Bayer color filter array)
-
LCD (Triangular pixel geometry)
-
CRT(shadow mask)
- Narrowscreen 4:3 computer display resolutions
- Analog
- Digital
- 500×480: Digital8
- 720×480: miniDV, Digital Betacam (NTSC)
- 720×480: Widescreen DVD (anamorphic) (NTSC)
- 854×480: EDTV (Enhanced Definition Television)
- 720×576: miniDV, Digital8, Digital Betacam (PAL/SECAM)
- 720×576 or 1024 x 576: Widescreen DVD (anamorphic) (PAL/SECAM)
- 1280×720: D-VHS, HD DVD, Blu-ray, HDV (miniDV)
- 1440×1080: HDV (miniDV)
- 1920×1080: HDV (miniDV), AVCHD, HD DVD, Blu-ray, HDCAM SR
- 1998×1080: 2K Flat (1.85:1)
- 2048×1080: 2K Digital Cinema
- 3840×2160: 4K UHDTV, Ultra HD Blu-ray
- 4096×2160: 4K Digital Cinema
- 7680×4320: 8K UHDTV
- 15360×8640: 16K Digital Cinema
- 30720x17280: 32K
- Sequences from newer films are scanned at 2,000, 4,000, or even 8,000 columns, called 2K, 4K, and 8K, for quality visual-effects editing on computers.
- IMAX, including IMAX HD and OMNIMAX: approximately 10,000×7,000 (7,000 lines) resolution. It is about 70 MP, which is currently highest-resolution single-sensor digital cinema camera (as of January 2012).[citation needed]
- Film
- 35 mm film is scanned for release on DVD at 1080 or 2000 lines as of 2005.
- The actual resolution of 35 mm
PPI | Pixels | mm |
---|---|---|
800 | 1000 | 31.8 |
300 | 1000 | 84.7 |
200 | 1000 | 127 |
72 | 1000 | 352.8 |
PPI | Pixels | mm |
---|---|---|
800 | 3150 | 100 |
300 | 1181 | 100 |
200 | 787 | 100 |
72 | 283 | 100 |
PPI | Pixels | mm | Paper size |
---|---|---|---|
300 | 9921×14008 | 840×1186 | A0 |
300 | 7016×9921 | 594×840 | A1 |
300 | 4961×7016 | 420×594 | A2 |
300 | 3508×4961 | 297×420 | A3 |
300 | 2480×3508 | 210×297 | A4 |
300 | 1748×2480 | 148×210 | A5 |
300 | 1240×1748 | 105×148 | A6 |
300 | 874×1240 | 74×105 | A7 |
300 | 614×874 | 52×74 | A8 |
- Modern digital camera resolutions
- Digital medium format camera – single, not combined one large digital sensor – 80 MP (starting from 2011, current as of 2013) – 10320 × 7752 or 10380 × 7816 (81.1 MP).[8][9][10][11]
- Mobile phone – Nokia 808 PureView – 41 MP (7728 × 5368), Nokia Lumia 1020 – also 41 MP (7712 × 5360)
- Digital still camera – Canon EOS 5DS – 51 MP (8688 × 5792)
See also
- Display resolution
- Dots per inch
- Multi-exposure HDR capture
- High-resolution picture transmission
- Image scaling
- Image scanner
- Kell factor, which typically limits the number of visible lines to 0.7x of the device resolution
- Pixel density
References
- ^ [1] Archived 2017-02-02 at the Wayback Machine Guideline for Noting Digital Camera Specifications in Catalogs. "The term 'Resolution' shall not be used for the number of recorded pixels"
- ^ ANSI/I3A IT10.7000–2004 Photography – Digital Still Cameras – Guidelines for Reporting Pixel-Related Specifications
- ^ "Video resolution comparison chart".
- ^ "Kodak VISION3 500T Color Negative Film 5219 / 7219 / SO-219" (PDF). July 2015.
- ^ [2] An analysis of film resolution
- ^ Understanding image sharpness part 1A: Resolution and MTF curves in film and lenses, by Norman Koren
- ^ "/Film Interview: IMAX Executives Talk 'The Hunger Games: Catching Fire' and IMAX Misconceptions". Slash Film. December 2, 2013. Retrieved December 17, 2013.
- ^ "Phaseone". Archived from the original on 2012-03-18.
- ^ "Leaf Aptus Medium Format Digital Backs". www.mamiyaleaf.com. Archived from the original on 2015-09-24. Retrieved 2013-11-06.
- ^ DxO. "Phase One IQ180 Digital Back: Tests and Reviews – DxOMark". www.dxomark.com.
- ^ Forret, Peter. "Megapixel calculator – toolstudio". web.forret.com.