Test image in accordance with EN IEC 62676-4 to check the image quality. The test method uses a standardized test target. It is used to evaluate the performance of a video surveillance system. The test charts are to be used as test targets and grouped as shown below.
Quality levels of images LPDO
(Low Pixel Density Object)
Quality levels of images HPDO
(High Pixel Density Object)
The test targets are easy to use for testing of coverage, determining acceptable image height, resolution, colour and contrast of the image. Each test target is placed at strategic positions within the area of coverage as definedby the operational requirements or system specification, and detectability at each location is confirmed. Thistest should be carried out over the total light range over which the system is intended to operate.
In order to obtain optimal image material for manhunt purposes, care must be taken to keep optical verticaldistortions as low as possible. Therefore, the vertical tilt angle of the fixed camera unit should not exceed 13°.
Notice for projection for Testcharts
Attention when compressing data, live-image and recorded image are to be compared!
In general, especially the performance feature „scrutinise“ can be guaranteed only for a part of the camera surveillance range.
Dead ranges depending of the mounting height are to be considered.
For cameras that can zoom and can be moved at least two reference images should be determined and documented.
HPDO (High Pixel Density Object)
1. If a clear distinction of the outer black/white fields of star 1 is possible, the quality level „scrutinise“ is reached.
2. If a clear distinction of the outer black/white fields of star 2 is possible, the quality level „validate“ is reached.
3. If a clear distinction of the outer black/white fields of star 3 is possible, the quality level „characterise“ is reached.
4. If a clear distinction of the outer black/white fields of star 4 is possible, the quality level „perceive“ is reached.
6. Six colours can be differentiated: raised colour aptitude NOTE: Apply a 50 % black filter on each colour from the first line
7. Eleven grey scale values, deep black (background of test panel) and pure white
8. Three grey scale values, deep black (background of test panel) and pure white
9. Centimetre ruler for determination of the field of view
10. + 11. Accident Prevention Regulation
The resolution is sufficient if the pattern „C“ and better „B“ and even better „A“ can be recognised at a recording width of 1.5 m. The resolution is sufficient if the pattern is recognisable at a recording width of 6 m.
LPDO (Low Pixel Density Object)
12. If a clear distinction of the outer black/white fields of star 1 is possible, the quality level „discern“ is reached.
13. If a clear distinction of the outer black/ white fields of star 2 is possible, the quality level „outline“ is reached.
14. If a clear distinction of the outer black/ white fields of star 3 is possible, the quality level „overview“ is reached.
Source: EN IEC 62676-4:2024, Video surveillance systems for use in security applications, Part 4: Application guidelines
