Institute of Control Systems and Industrial Computing (AI2), Universitat Politècnica de València (UPV), 46022 València, Spain.
Institut d'Investigació per a la Gestió Integrada de Zones Costaneres (IGIC), Universitat Politècnica de València (UPV), 46022 València, Spain.
Sensors (Basel). 2020 Sep 16;20(18):5294. doi: 10.3390/s20185294.
A proposal is described for an underwater sensor combining an acoustic device with an optical one to automatically size juvenile bluefin tuna from a ventral perspective. Acoustic and optical information is acquired when the tuna are swimming freely and the fish cross our combined sensor's field of view. Image processing techniques are used to identify and classify fish traces in acoustic data (echogram), while the video frames are processed by fitting a deformable model of the fishes' ventral silhouette. Finally, the fish are sized combining the processed acoustic and optical data, once the correspondence between the two kinds of data is verified. The proposed system is able to automatically give accurate measurements of the tuna's Snout-Fork Length (SFL) and width. In comparison with our previously validated automatic sizing procedure with stereoscopic vision, this proposal improves the samples per hour of computing time by 7.2 times in a tank with 77 juveniles of Atlantic bluefin tuna (), without compromising the accuracy of the measurements. This work validates the procedure for combining acoustic and optical data for fish sizing and is the first step towards an embedded sensor, whose electronics and processing capabilities should be optimized to be autonomous in terms of the power supply and to enable real-time processing.
描述了一种将声学设备与光学设备相结合的水下传感器，用于自动从腹侧视角对幼龄蓝鳍金枪鱼进行尺寸测量。当金枪鱼自由游动并穿过我们组合传感器的视场时，会同时获取声学和光学信息。图像处理技术用于识别和分类声学数据（声图）中的鱼类痕迹，而视频帧则通过拟合鱼类腹侧轮廓的可变形模型进行处理。最后，通过验证两种数据之间的对应关系，将处理后的声学和光学数据进行组合，以确定鱼类的尺寸。所提出的系统能够自动准确测量金枪鱼的吻肛长（SFL）和宽度。与我们之前经过验证的立体视觉自动尺寸测量程序相比，在一个装有 77 条大西洋蓝鳍金枪鱼幼鱼的水槽中，该方案将每小时的计算样本数提高了 7.2 倍，而测量精度不受影响。这项工作验证了结合声学和光学数据进行鱼类尺寸测量的方法，是迈向嵌入式传感器的第一步，该传感器的电子设备和处理能力应针对电源进行优化，以实现自主运行，并支持实时处理。
