System for external fish parasite monitoring in aquaculture

Patent metadata

Field	Value
Publication number	US-11825814-B2
Application number	US-201816768904-A
Country	US
Kind code	B2
Filing date	Dec 19, 2018
Priority date	Dec 20, 2017
Publication date	Nov 28, 2023
Grant date	Nov 28, 2023

Abstract

A system for external fish parasites monitoring in aquaculture, the system comprising: —a camera ( 52 ) suitable to be submerged in a sea pen suitable for containing comprising fish, the camera being arranged for capturing images of the fish; and—an electronic image processing system ( 86 ) configured for identifying external fish parasites on the fish by analyzing the captured images, wherein: —a ranging detector ( 54 ) configured for detecting the presence of fish and measuring a distance from the detector to the fish is mounted adjacent to the camera ( 52 ); and—an electronic control system ( 12 ) is arranged to control a focus of the camera ( 52 ) on the basis of the measured distance and to trigger the camera ( 52 ) when a fish has been detected within a predetermined distance range.

First claim

The invention claimed is:

1. A system for automated external fish parasites monitoring in aquaculture, the system comprising:
a camera ( 52 ) suitable to be submerged in a sea pen ( 40 ) suitable for containing fish ( 72 , 74 ), the camera being arranged for capturing images of the fish; and
an automated electronic image processing system ( 78 ) configured for identifying external fish parasites on the fish by analyzing the captured images,

characterized in that:
a ranging detector ( 54 ) configured for detecting the presence of fish and measuring a distance from the detector to the fish is mounted adjacent to the camera ( 52 ); and
an electronic control system ( 12 ) is arranged to control a focus of the camera ( 52 ) on the basis of the measured distance and to trigger the camera ( 52 ) when a fish has been detected within a predetermined distance range in which the distance is larger than the distance at which a typical fish spans the entire horizontal viewing angle of the camera and smaller than the distance at which the angular resolution of the camera can no longer resolve the smallest external fish parasites.

2. The system according to claim 1 , wherein the ranging detector ( 54 ) comprises:
emit optics ( 58 ) for emitting light; and
receive optics ( 60 ) adapted to receive reflected light and to measure a time of flight of the received light.

3. The system according to claim 2 , wherein the emit optics ( 58 ) is configured to emit light in the form of a fan spread over an extended angular range in vertical direction and collimated in horizontal direction.

4. The system according to claim 3 , wherein the receive optics ( 60 ) includes a plurality of detector elements having adjacent fields of view ( 66 ) which collectively form a vertically oriented acceptance fan ( 68 ), the ranging detector being adapted to measure bearing angles (□) under which reflected light is detected by the individual detector elements.

5. The system according to claim 1 , wherein the electronic image processing system ( 78 ) comprises a fish detector ( 84 ) configured to recognize a silhouette of a fish in the captured image, and an external fish parasite detector ( 86 ) configured to detect external fish parasites in a specified region ( 90 - 100 ) within the silhouette of the fish ( 72 ).

6. The system according to claim 5 , wherein the electronic image processing system ( 78 ) comprises at least one neural network constituting the fish detector ( 84 ) and/or the external fish parasite detector ( 86 ).

7. The system according to claim 1 , comprising a camera and lighting rig ( 10 ) having a vertical support member ( 14 ), an upper boom ( 16 ) articulated to a top end of the support member ( 14 ) and carrying an upper lighting array ( 22 ), a lower boom ( 18 ) articulated to a lower end of the support member ( 14 ) and carrying a lower lighting array ( 24 ), and a housing ( 20 ) attached to the support member and carrying the camera ( 52 ) and the ranging detector ( 54 ), wherein the upper and lower lighting arrays ( 22 , 44 ) are configured to illuminate, from above and from below, a target region inside a field of view of the camera ( 52 ).

8. The system according to claim 7 , wherein the upper lighting array ( 22 ) is configured to emit light with an intensity and/or spectral composition different from that of the light emitted by the lower lighting array ( 24 ).

9. The system according to claim 8 , wherein the upper lighting array ( 22 ) comprises a flash tube unit, and the lower lighting array ( 24 ) comprises an LED lighting unit.

10. The system according to claim 7 , comprising a posture sensing unit ( 56 ) adapted to detect a posture of the camera and lighting rig ( 10 ) relative to the sea pen ( 40 ).

11. The system according to claim 1 , wherein the electronic control system ( 12 ) is configured to control the camera ( 52 ) so as to capture a sequence of images in an extended time interval in which the ranging detector ( 54 ) continuously detects the fish within the predetermined distance range.

12. A method for external fish parasites monitoring in aquaculture, characterized by using the system according to claim 1 .

13. A method for automated external fish parasites monitoring in aquaculture, comprising the steps of:
submerging a camera ( 52 ) in a sea pen ( 40 ) comprising fish ( 72 , 74 );
capturing images of the fish ( 72 , 74 ) with the camera ( 52 ); and
identifying external fish parasites on the fish ( 72 , 74 ) by automated electronic image analysis of the captured images,

characterized by the steps of:
operating a ranging detector ( 54 ) to continuously monitor a part of the sea pen ( 40 ) for detecting the presence of fish in that part of the sea pen and, when a fish has been detected, measuring a distance from the camera ( 52 ) to the fish ( 72 , 74 ); and
when a fish has been detected, calculating a focus setting of the camera ( 52 ) on the basis of the measured distance; and
triggering the camera ( 72 ) when the detected fish ( 72 , 74 ) is within a predetermined distance range in which the distance is larger than the distance at which a typical fish spans the entire horizontal viewing angle of the camera and smaller than the distance at which the angular resolution of the camera can no longer resolve the smallest external fish parasites.

14. The method according to claim 13 , wherein the electronic image processing system ( 78 ) is used for detecting fish ( 72 , 74 ) in an image captured by the camera ( 52 ) and for detecting external fish parasites within a silhouette of the detected fish.

15. The method according to claim 14 , wherein the ranging detector ( 54 ) is used for measuring a bearing angle of a detected fish ( 72 ), and the measured bearing angle is used in the machine vision system ( 78 ) for searching for the silhouette of the fish in the captured image.

16. The method according to claim 13 , wherein a target region bounded by a field of view of the camera ( 52 ) and by said predetermined distance range is illuminated from above and below with light of different intensities and/or spectral compositions.

17. The method according to claim 16 , wherein the step of detecting the presence of external fish parasites at a given location on the fish includes distinguishing whether said given location is in a top side region ( 90 ) or a bottom side region ( 92 ) of the fish.

18. The method according to claim 13 , comprising:
distinguishing between at least two different classes of external fish parasites which differ in the difficulty of recognizing the external fish parasites;
calculating quality metrics for each captured image, the quality metrics permitting to identify the classes of external fish parasites for which the quality of the image is sufficient for external fish parasites detection; and
establishing separate detection rates for each class of external fish parasites, each detection rate being based only on images the quality of which, as described by the quality metrics, was sufficient for detecting external fish parasites of that class.

19. A method for external fish parasites monitoring in aquaculture, characterized by using the system according to claim 5 .

20. A method for external fish parasites monitoring in aquaculture, characterized by using the system according to claim 7 .

Assignees

• Intervet Inc

Inventors

• Howe Russel
• Lizer Zachary
• Sarrett James Wallace
• Abrahamson Peter Jon
• Little Jascha Tucker

Classifications

• A01K61/13 Primary

  Prevention or treatment of fish diseases · CPC title

• A01K63/06

  Arrangements for heating or lighting in, or attached to, receptacles for live fish · CPC title

• G01S17/04

  Systems determining the presence of a target · CPC title

• G01S17/08

  for measuring distance only (indirect measurement G01S17/46; active triangulation systems G01S17/48) · CPC title

• G03B15/03

  Combinations of cameras with lighting apparatus; Flash units · CPC title