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Dimensions: 875 x 492     IR: 433 KPX     JPG: 159 KB
Dimensions: 2748 x 1546     IR: 4.25 MPX     JPG: 1.23 MB
Dimensions: 8688 x 4888     IR: 42.47 MPX     JPG: 9.82 MB
 
Better Image Resolution
Bytes, JPGs and pixels, oh my! Image Resolution has several definitions. The definitions are technology specific such as:
 •
Camera Resolution (CR) and Image Resolution (IR), which are measured in pixels.
 •
optical device resolution, where it is measured in lines/mm.
 •
printed resolution, which is measured in dots/inch.
The focus here is on improving IR while producing an accurate reproduction of the subject. Computer generated enhancements to "sharpen" images alter the subject.
Applicability
The following discussion covers cameras which offer pixel choices for still images. For example, a 48 MPX camera might also offer 24 MPX and 12 MPX CR settings. Such options are normally found in device setups dealing with file format, file size, or CR.
CRs, IRs & Files
Refer to the following table during this discussion.
Examples
CR

AR

Dimensions
(PX)

IR

JPG
File Size

50 MPX

16:9

8688 : 4888

42.5 MPX

8 MB - 15.9 MB

32 MPX

16:9

6960 : 3904

27.17 MPX

5.5 MB - 13.5 MB

24 MPX

16:9

6000 : 3368

20.2 MPX

4 MB - 9.5 MB
 •
CR examples are DSLR camerass from one manufacturer.
 •
ARs are the same to eliminate a minor source of variability in IR. The IRs for ARs of 3:2, 4:3 and 16:9 are within 2%.
 •
Dimensions are an image's width and height in pixels. For a particular camera and AR setting all images produced will have the same dimensions.
 •
IR is calculated by multiplying the image's width by its height.
 •
JPG File Sizes is the image's file size when rendered and stored. The range of file sizes for a particular IR is due to image content.
Conclusions
 •
There is a direct relationship between displayed image sharpness and its IR.
 •
Image file size increases as image IR increases .
 •
For a camera's highest IR select the highest CR.
 •
Time for a new camera?

Glossary
Aspect Ratio
Aspect Ratio, of an image, is the proportional relationship between its width and height. An image 8688 PX wide and 4888 PX high has an AR of 16:9 (or 1.78:1). Smart (HDMI) TVs have an AR of 16:9.
Byte
In basic terms, a byte is a unit of digital (computer) storage. Image file size is measured in bytes.
DSLR
An acronym for camera type Digital Single Lens Reflex.
HDMI
An acronym for digital audio/video format High-Definition Multimedia Interface.
K
Times one thousand.
M
Times one million.
Metadata
Image file Metadata includes: Item type (e.g., JPG), Date taken (date & time), Dimensions (width x height, in PX) and Size (bytes). Image file Metadata is available in your PC's file managing app.
Pixel
Pixel stands for "Picture Element" and is abbreviated PX. .