Zhang Qinchuan

Effect of Smoothing Filters on Time-Domain Waveform Image Segmentation

In this paper, we studied the effect of smoothing filters on the segmentation of Time-domain wave form image (TDWI). The positive and negative impacts of global and localized smoothing operator shave analyzed and forwarded our conclusions. We used two class of images for the experiment, ordinary Lena test images, and Time-domain waveform images. All images are first converted to the grayscale then segmented without smoothing and after smoothing with both global and localized filters, the results are compared using a visual comparison, Peak Signal to Noise Ratio (PSNR) and Means Squared Error (MSE).There are lots of studies that generally recommend using general smoothing operators for better output of image segmentation on various applications. But we realized that smoothing TDWIs needs special attention on selecting the type of smoothing operators to use. Using the global smoothing operators before segmentation has shown a deleterious impact on the pertinent information of the segmented waveform. The experiments proved that the effect is drastic and fatal to the entropy of waveform because the Region of Interest (ROI) on the image is a tiny line structure with a width consisting only a few pixels. As a result of the large mask window of the global operator, the central pixel intensity may average out to the other region which inturn leads to change in shape of the wave form. This is significant to change the pertinent information. But using localized smoothing filters have shown outperforming results. Thus we propose to avoid using global smoothing operators during segmentation of TDWIs. But localized smoothing filters with simple basic image enhancement techniques are strongly recommended.

New method for measurement of waveform capture rate using random signal

Waveform capture rate is one of the most important indicators of digital storage oscilloscope, representing the ability of the system to capture waveforms in unit time. But for the actual acquisition systems, it is difficult to measure this indicator only by its external characteristics. In this paper, by analyzing the relation between the waveform capture rate and the dead-time of DSO, the new measurement method based on random pulse signal for waveform capture rate is proposed, and then this method has been verified in the actual system and gives the test results accordingly.

Research on an efficient method of auto set of digital oscilloscope

The method of auto set makes it more convenient for users to capture and observe the unknown signal. It focuses on some related key technologies which are discussed in detail in the paper, such as initialize, judge whether all input channels are signaled or not, search vertical sensitivity by binary search method only if the channel has signal, set up the vertical sensitivity when multipath signals need to separate by the related software method, display the bias voltage, setup gear of time base according to the base-time system. And the experimental results are presented; the efficiency of complete design scheme is much higher than before.