Detect shrimps on the photo

Python
1

Sory if my English is not good
I have to detect shrimps on the photo. Some things are not shrimp was detected. Is there any way to remove it. Thank.

2022-09-13_15h23p51s
2022-09-13_15h23p51s1920×1080 30.7 KB

Result:
opencv

Code:

import cv2
import numpy as np
import matplotlib.pyplot as plt

image = cv2.imread(r'E:\1-LUANVAN_Code\image\hinhchupkhongro\13-09-2022\2022-09-13_15h23p51s.png')

copyimage = image.copy()

enhimg = cv2.detailEnhance(image, sigma_s=100, sigma_r=0.15)

grayimg = cv2.cvtColor(enhimg, cv2.COLOR_BGR2GRAY)

smoothimg = cv2.edgePreservingFilter(grayimg, flags=1, sigma_s=30, sigma_r=0.15)

thresh = cv2.adaptiveThreshold(smoothimg, 255, cv2.ADAPTIVE_THRESH_GAUSSIAN_C, cv2.THRESH_BINARY_INV, 101, 2)

contours, hierarchy = cv2.findContours(thresh, cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)

mask = np.zeros_like(image)

for contour in contours:
    if cv2.contourArea(contour)>4000:
        cv2.drawContours(mask, contour, -1, (255,255,255), 1)
        x,y,w,h = cv2.boundingRect(contour)
        cv2.rectangle(copyimage, (x,y), (x+w, y+h), (255,0,0), 5)

plt.figure('Opencv')

plt.subplot(2,2,1)
plt.xticks([]), plt.yticks([]), plt.title('Image')
plt.imshow(image, cmap='gray')

plt.subplot(2,2,2)
plt.xticks([]), plt.yticks([]), plt.title('Threshold')
plt.imshow(thresh, cmap='gray')

plt.subplot(2,2,3)
plt.xticks([]), plt.yticks([]), plt.title('Mask')
plt.imshow(mask, cmap='gray')

plt.subplot(2,2,4)
plt.xticks([ ]), plt.yticks([]), plt.title('Result')
plt.imshow(cv2.cvtColor(copyimage, cv2.COLOR_BGR2RGB))

plt.savefig('opencv.png')

plt.show()