JAI AD-081 Manual, Tech Note

1, Tech Note TN-0902 Date: 02/06/09 USING A 2CCD CAMERA TO CREATE HIGH-DYNAMIC RANGE IMAGES Some imaging scenarios push dynamic range beyond the capabilities of the typical sensor. This is especially true where incident light is present (e.g., imaging a light source and the surro…

2, Tech Note 2 NO. TN-0902 pg 2 Example 1 - Maximum Dynamic Range (no overlap) To create an image that spans the maximum range of light intensities, use shutter settings to calibrate the 2 sensors so that Sensor B = Sensor A * 1024. In other words, the light needed to generate 100 counts f…

3, Tech Note 2 Displaying a high dynamic range image on a standard monitor will require mapping the output to t the monitor’s dynamic range capability. For the image described above, start by creating a 20-bit image map using the raw pixel data. Then create a 10-bit image map t…

4, Tech Note 2 Now, our post processing routine could be handled as follows: if (pixel B < 16){ pixel_out = pixel A }else{ pixel_out = pixel B * 64 } By overlapping the two sensor responses, this approach utilizes the full precision of the lower 10-bits while reducing the e…

5, JAI AD-081 Tech Note 2 Now as Sensor A approaches its saturation point (512 – 1023 counts) the output uses the average of both sen- sors’ data to “smooth” the transition between the two sensor response graphs (see Figure 6). It still limits the use of the lowest bits on Sensor B (those that are m…

6, Tech Note 2 For example, in a 4-bit overlap scenario, we still set the shutter for Sensor B to be roughly 64 times faster than Sensor A (i.e., a pixel on Sensor A with a value of 256 would have a value of 4 on Sensor B). But, de- pending on our objective, we apply a post processing …