Research on CCD board computer image test

1. Testing the image effect of CCD board machine is a big project. Prepare the test chart and prepare the color bar light box conditionally, but that thing is too expensive and few people have it. Today we mainly talk about how to test the effect of CCD board machine with the test chart.


1) It is usually placed a few meters away from the camera, and the lens is adjusted to the clearest place for fixation. At the same time, the number of lines of the camera can be roughly known through comparison, and the clarity of several cameras and the general performance effect of wide dynamic can be compared. When carefully debugging a camera, we must pay attention to science. An excellent camera affects the normal performance of quality because of poor debugging. Therefore, when debugging the camera, we must come up with a good surveillance camera lens in strict accordance with the technical process: usually 8 or 9 mm, manual aperture and two variable lenses are used. The lens is very important. We should make good use of the lens, Seiko lens or Computar lens

2) If the color resolution is higher than 500, it is better to use the color knob to analyze the color, but it is better to use the high resolution monitor, and set the color to the middle.

3) A test drawing of surveillance camera

Start test: 1 Align the test chart, align the surveillance camera with the center of the test chart, and adjust the distance between the surveillance camera and the test chart until the "pattern" displayed on the display "just" occupies the whole screen, that is, "the four corners of the test chart are in the box", if the monitor is displayed! 2) , place an incandescent lamp on both sides of the test chart and shine it on the chart at an angle of 45 degrees, so that there is uniform light on the surface of the chart The surveillance camera shall be installed on the tripod or bracket as far as possible 4 Turn off the backlight compensation (BLC) of the surveillance camera, turn off the automatic gain (AGC), and set the white balance at ATW,

Switch to AES (automatic electronic shutter, that is, the gear for installing manual lens), open the lens aperture to the maximum, adjust the focal length, and adjust the image to the clearest. At this time, there is a circle of radiation in the middle of the test map, indicating that the focus target map is used for focusing. Remember, the test map still needs to cover the whole camp screen, no more or less (four corners into the frame)

Then switch the surveillance camera AES / ALC to ALC, that is, connect the automatic aperture, and the screen will turn white! Turn down the lens aperture by about 1 / 3 until the image is restored correctly. If you go too far, you should start again, that is, turn the aperture to the maximum first and then turn it back. You can't dim it first and then light it up

Resolution test: carefully look at the four lines in the test chart that form a bundle upward (of course, look at the lines in the screen). From bottom to top, it becomes more and more dense until the four lines are almost closed, and it is impossible to distinguish each part. Remember, this is the point. Look back at the test view, and find out the number of lines next to that point, which is the resolution of the surveillance camera! The error of this test method will not exceed 20

For bandwidth test, look at a row of dense straight lines (indicating bandwidth in MHz) at the top left of the test diagram. Look at the screen, which one is barely divided clearly. The following number is the bandwidth of the surveillance camera. This data is for reference only. Generally speaking, the higher the resolution, the greater the bandwidth of the machine

There is a concentric circle in each of the four corners of the CCD flatness test chart, as shown in the right figure: this has two functions: 1 Use to see if the test chart is placed correctly. If it is placed correctly, the four circle charts should be as clear as before. 2 When placed correctly, if one or two concentric circles will lose focus, it means that the CCD is uneven and should be returned

There is a large black-and-white strip on the left of the impedance matching test diagram: if the black area seeps into the white area or the white seeps into the black area, it indicates that there is a problem with your impedance matching, or there is a reflected signal. It may be that the connector is not done well, there is a problem with the wire, etc. this method can be used to test the impedance matching during long-distance wire transmission

Color reduction

Using the color bar on the test chart: compare what you see from the monitor with what you see on the actual test chart, you can easily see the color restoration degree of the surveillance camera In fact, this is the most difficult to measure. How do you determine whether the surveillance camera is wrong or the color of the monitor is wrong? If you think your monitor is good, put the color, brightness and contrast buttons in the middle If you are not sure that the monitor is OK, you can get a test disc and get the monitor color right

ATW (automatic white balance) test automatically tracks the white balance. When testing the above color reduction degree, switch the light source, such as natural light, fluorescent lamp, bulb and other light sources. A good surveillance camera can quickly find the correct color when switching under different color temperatures. Some machines will turn red when suddenly moving out of the window under the bulb, or turn blue when moving out of the window quickly, which is the poor design of white balance.


Because testing the image effect of CCD board machine is the main content of our testing. Today, we talk in detail. I hope you can taste it well. Testing a CCD board machine is not a matter that can be done in two or three times. Friends without test chart can contact Shenzhen zhenkung Fu. We can provide you with CCD board test chart for free. If there is any good test method, we hope you can contact us. Shenzhen Jinjia technology expresses its thanks to you!