By analyzing the characteristic of wavelet transform and the image s edge and texture features,the truncation point thresholds of rate-distortion slope were predicted linearly based on the image data compression ratio,which were modified dynamically to meet the requirements of the bit-rate during the encoding procedure.

Considering the physical features and computing requirements of in-water profile spectral data,the cut-off point method is adopted to identify the outliers in in-water profile spectral data,and is compared with the other two common methods(the triple standard difference method,ratio method proposed in ProSoft software).

Then,the subsequent part of the pulse energy will be strongly absorbed by the laser plasma,the light will be suspended,and this moment is defined as the cut-off time.