AS ISO 20954.1 pdf download

AS ISO 20954.1 pdf download.Digital cameras — Measurement for image stabilization performance
1  Scope
This document defines the measurement method of optical image stabilization performance for still images compensating for handheld blur consisting of two rotational components, yaw and pitch. It applies to consumer digital cameras with optical image stabilization for still images. Apparatuses such as camcorders and mobile phones with still image shooting functionality are within the scope of this document.
2  Normative references
There are no normative references in this document.
3  Terms and definitions
For the purposes of this document, the following terms and definitions apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: — ISO Online browsing platform: available at https:// www .iso .org/ obp — IEC Electropedia: available at http:// www .electropedia .org/ 3.1 image stabilization camera function that prevents handheld blur by using a means of camera movement detection Note 1 to entry: Even if a camera function uses a means of camera movement detection, it is not regarded as an image stabilization function if its primary means of blur mitigation is shortening exposure time based on exposure control program optimization. 3.2 optical image stabilization function that compensates for image displacement on the focal plane due to movement of a handheld camera by moving a part or whole of the optical system and/or image sensor, based on a means of camera movement detection 3.3 handheld blur loss of image sharpness caused by movement of a handheld camera during exposure 3.4 stop number that expresses a doubling or halving of the amount of light let in when taking a picture and which is typically represented by an exposure value Note 1 to entry: For instance, the difference between exposure times of 1/1 000 s (TV10) and 1/500 s (TV9) or 1/125 s (TV7) and 1/60 s (TV6) is one stop. Note 2 to entry: “TVn” expresses that time value of APEX equals to n. See Annex C of Reference [5] for APEX.3.5 handheld blur threshold level of handheld blur at which image stabilization performance is determined Note 1 to entry: In this document, this level is 63 μm of motion in the focal plane on one frame of 35 mm film, where one frame means the picture size (24 mm × 36 mm). 3.6 average vibration angle expected deflection angle of camera rotation under handheld vibration during exposure Note 1 to entry: The handheld vibration is given as the vibration waveform data that is specified in document. Note 2 to entry: The average vibration angles are given as amount of angle in degrees of each exposure time as shown in Figure 7. The values are statistical expectation and are calculated from average of oscillation amplitude from peak to bottom of the vibration waveform when certain exposure time is applied. 3.7 35 mm film equivalent focal length focal length of a lens attached to a camera with a sensor size of 24 mm × 36 mm (originated from 35 mm film) that produces the same field of view as the camera system with a lens at a given focal length for which the 35 mm sensor equivalent focal length is specified
4  Measurement method
4.1  General The objective of this document is to specify how to measure optical image stabilization performance of a camera held in the user’s hands. Accordingly, a measurement session would better simulate a real shooting situation if the camera was actually held by a test photographer. However, this makes it difficult to eliminate variation among individual photographers or how well the camera is designed for handheld shooting. In order to cancel these effects, the test camera shall be mounted on a vibration generator that shakes the camera with a simulated handheld vibration waveform, and image stabilization performance shall be measured with images of a test chart specified by this document. This document specifies two waveforms that simulate the important characteristics of how a camera shakes when it is held by hand. These waveforms were developed by analysing extensive measurement data and adding further theoretical observations. Figure 1 shows an overview of the measurement method. Annex E collaterally gives additional explanations for background of specifying measurement method, vibration generator, vibration waveform and reference information.