User Guide

Figure 25 Good image taken outdoors

Image quality analysis

Possible faults in image quality

When checking for possible errors in camera functionality, knowing what error is suspected significantly

helps the testing by narrowing down the amount of test cases. The following types of image quality problems

may be expected to appear:

• Dust (black spots)

• Lack of sharpness

• Bit errors

In addition, there are many other kinds of possibilities for bad image quality, but those are ruled out from

the scope of this document since the probability of their appearance is small.

Testing for dust in camera module

Symptoms and diagnosis

For detecting these kinds of problems, take an image of a uniform white surface and analyse it in full

resolution. A good quality PC monitor is preferred for analysis. Search carefully, since finding these defects

is not always easy. Figure "Effects of dust on optical path" is an example image containing easily detectable

dust problems.

When taking a white image, use uniformly lightened white paper or white wall. One possibility is to use

uniform light but in this case make sure that the camera image is not flickering when taking the test image.

In case flickering happens, try to reduce illumination level. Use JPEG image format for analysing, and set the

image quality parameter to ‘High Quality’.

RA-6

Camera Module Troubleshooting

Issue 1 COMPANY CONFIDENTIAL Page 5 –11