Counting and measuring the size and stomach fullness levels for an intelligent shrimp farming system

Figures & data

Figure 1. Experimental environment. (a) Sketch of the pond. (b) The actual pond.

Figure 2. Overall process flow of the proposed method.

Figure 3. Network architecture of AR-YOLOv5.

Figure 4. Training process of AR-YOLOv5.

Figure 5. The side length definition.

Figure 6. Comparison of the size estimation methods between regular YOLOv5 and the proposed method in the overlapping shrimps. (a) Regular YOLOv5. (b)(c) Regular YOLOv5 failed to estimate size by segmentation. (d) Our angle detection-based size estimation result.

Table 1. Degree of stomach fullness mapping to Full/Empty.

Degree of fullness	Stomach Fullness Level $(\mathbf{\%})$	Class in this experiment
empty / full	0 / 100	Empty / Full
nearly 0	5.0	Empty
$<\frac{1}{4}$ full	12.5	Empty
$\frac{1}{4}$ full	25.0	Empty
$\frac{1}{4}<\frac{1}{2}$ full	37.5	Empty
$\frac{1}{2}$ full	50.0	Full
$\frac{1}{2}<\frac{3}{4}$ full	62.5	Full
$\frac{3}{4}$ full	87.5	Full

Figure 7. Inner bounding box and Outer bounding box of shrimp were used to calculate the stomach fullness levels.

Figure 8. Highlight of the shrimp’s digestive tract segmented using Otsu’s thresholding method.

Figure 9. Loss function value curve: Comparison of the Loss for five different AR-YOLOv5 models on the training set.

Figure 10. PR curve: Performance comparison of the five different AR-YOLOv5 models on the testing set.

Table 2. Comparison of different models with data preprocessing.

Method	$\mathit{P}(\mathbf{\%})$	$\mathit{R}(\mathbf{\%})$	${\mathit{F}}_1(\mathbf{\%})$	$\mathit{m}\mathit{A}\mathit{P}(\mathbf{\%})$
AR-YOLOv5n	97.58	86.38	91.64	92.42
AR-YOLOv5s	97.63	88.57	91.84	94.06
AR-YOLOv5m	97.65	89.26	93.27	94.71
AR-YOLOv5l	96.18	90.71	93.36	94.60
AR-YOLOv5x	97.70	91.42	94.46	95.42

Table 3. Comparison of different models without data preprocessing.

Method	$\mathit{P}(\mathbf{\%})$	$\mathit{R}(\mathbf{\%})$	${\mathit{F}}_1(\mathbf{\%})$	$\mathit{m}\mathit{A}\mathit{P}(\mathbf{\%})$
AR-YOLOv5n	96.80	86.42	91.32	92.38
AR-YOLOv5s	97.63	88.57	92.88	93.73
AR-YOLOv5m	97.56	85.71	91.25	92.51
AR-YOLOv5l	97.50	83.57	90.00	91.48
AR-YOLOv5x	96.60	81.40	88.35	89.60

Figure 11. A four-months growth Shrimps length estimation and its error percentage.

Table 4. Absolute measurement error and error percentage of shrimp’s quantity.

Sample point	True value	Estimated value	Absolute error	Error percentage$(\mathbf{\%})$
1	17	14	3	17.6
2	9	8	1	11.1
3	6	5	1	16.7
4	20	13	7	35
5	12	11	1	8.3
6	8	9	1	12.5
7	12	12	0	0
8	8	7	1	12.5
9	16	16	0	0
10	13	13	0	0
average	12.1	10.8	1.5	11.3

Figure 12. Example of stomach fullness levels. Top row: Stomach fullness level $<$ 12.5%. Middle row: 12.5% $\le$ Stomach fullness level $<$ 50.0%. Bottom row: Stomach fullness level $\ge$50.0%.

Table 5. Evaluation metric results of two different methods.

Method	Shrimps	Accuracy $(\mathbf{\%})$	P $(\mathbf{\%})$	R $(\mathbf{\%})$	${\mathit{F}}_1(\mathbf{\%})$
Method 1.	169	88.8	91.7	90.9	91.3
Method 2.	169	91.1	98.9	86.2	98.9