The ISO camera resolution image card is produced in accordance with the ISO-12233:2000 standard. The resolution of the wedge plot test is 100 to 2000 lines per image height.

There are two types of processes: photographic or inkjet printing

Available sizes

0.5X : 10cmX17.8cm

1X: 20cmX35.6cm

2X: 40X71.1cm

4X: 80X142.2cm

8X: 160X284.4cm

scope of application

The ISO12233 standard is applicable to the clarity analysis of image and video capture devices such as civilian still photo digital cameras (DSC), mobile phones, surveillance cameras, etc. When recording the resolution of still photos in product catalogs, some products use the measurement method specified in this standard.

Reference standards and documents

The following standards are referenced in this standard, which will be part of the provisions of this standard. These reference standards are applicable to their latest versions (including additional content).

ISO12233：2000 Photography-Electronic still-picture cameras - resolutionmeasurements

ISO7589：2002 Photography–Illuminants forsensitometry-Speccificationsfordaylight,incandescent tungsten and printer

Terms and definitions

a) Resolution resolution

The limit of distinguishing fine patterns, except for jagged edges. Expressed as the number of lines per unit height of the screen.

b) Serrated aliasing

When the sampling frequency is less than twice the highest frequency of the image signal, noise with overlapping waves will be generated near the high-order harmonics of the sampling frequency.

Introduction to ISO Test Cards

1. ISO12233 Resolution Test Card

This standard is based on 12233, and the test charts also directly use ISO12233 charts. ISO charts contain various styles, and this standard (visual resolution) mainly uses the horizontal directions J1 and K1; J2 and K2 in the vertical direction; JD, KD and other styles tilted at a 45 degree angle.

When using ISO charts, it is not necessary to directly use the chart. You can also cut out the necessary parts and use them after reassembling and arranging them.

2. The meanings of the numbers recorded in ISO charts

When taking photos, ensure that the effective height of the chart occupies the entire image, and the number * 100 of the pattern is the number of bars per unit height in the image When shooting, it is not necessary to fill the entire frame with the effective height, but calibration is required at this time

3. Charts other than ISO charts

You can also create and use charts that are the same as ISO charts. At this point, the following requirements specified in ISO12233 must be met.

a) The ratio of the reflectance Rmax of the white background to the reflectance Rmin of the large black area is 80>Rmax>Rmin>40.

b) The positional accuracy of each pattern relative to the specified position is 0.2mm (+-0.1% of the screen height).

c) The line width is+-5%.

d) The reflectance ratio Rmax/Rmin of the thinnest parts (white and black parts) of hyperbolic patterns K1 and K2 is 18 or above. But this is only at the "recommended" level (Annex B of ISO 12233).

Transparent charts can also be used. At this point, the reflectivity of the above project should be explained as transmittance. When using a transparent chart, use diffused light for illumination. Whether reflective or transmissive, the evaluation pattern must exhibit neutral spectral characteristics.

Help

The ISO12233 resolution test card includes three resolution testing methods, as follows:

1. SFR testing

2. MTF test (frequency line test)

3. TVLine Test (Wedge Line Test)

SFR testing must be done using software testing, so we won't go into too much detail here; The frequency line test can be observed with the naked eye. As shown in the following figure:

Here we mainly explain the wedge-shaped line test.

Advantages of Wedge Line Testing:

1. Very intuitive, observable with the naked eye;

2. The testing requirements are relatively low compared to SFR;

3. Large data coverage, more accurate than frequency line testing;

Software can be used to assist in testing and obtain more accurate data.