zoom and pan

Can someone help me with this code here found from this forum **https://answers.unity.com/questions/1280592/pinch-and-zoom-functionality-on-canvas-ui-images.html#** the zoom in and pinch and Pan works absolutely fine but when zooming out it zooms out too much without a limit, how to limit the zooming out to the size of the original image(to zoom out max to the original scene size)

  using System.Collections;
  using System.Collections.Generic;
  using UnityEngine;
  using UnityEngine.UI;
  public class PinchableScrollRect : ScrollRect
  {
      [SerializeField] float _minZoom = .1f;
      [SerializeField] float _maxZoom = 10;
      [SerializeField] float _zoomLerpSpeed = 10f;
      float _currentZoom = 1;
      bool _isPinching = false;
      float _startPinchDist;
      float _startPinchZoom;
      Vector2 _startPinchCenterPosition;
      Vector2 _startPinchScreenPosition;
      float _mouseWheelSensitivity = 1;
      bool blockPan = false;
  
      protected override void Awake()
      {
          Input.multiTouchEnabled = true;
      }
  
      private void Update()
      {
          if (Input.touchCount == 2)
          {
              if (!_isPinching)
              {
                  _isPinching = true;
                  OnPinchStart();
              }
              OnPinch();
          }
          else
          {
              _isPinching = false;
              if (Input.touchCount == 0)
              {
                  blockPan = false;
              }
          }
          //pc input
          float scrollWheelInput = Input.GetAxis("Mouse ScrollWheel");
          if (Mathf.Abs(scrollWheelInput) > float.Epsilon)
          {
              _currentZoom *= 1 + scrollWheelInput * _mouseWheelSensitivity;
              _currentZoom = Mathf.Clamp(_currentZoom, _minZoom, _maxZoom);
              _startPinchScreenPosition = (Vector2)Input.mousePosition;
              RectTransformUtility.ScreenPointToLocalPointInRectangle(content, _startPinchScreenPosition, null, out _startPinchCenterPosition);
              Vector2 pivotPosition = new Vector3(content.pivot.x * content.rect.size.x, content.pivot.y * content.rect.size.y);
              Vector2 posFromBottomLeft = pivotPosition + _startPinchCenterPosition;
              SetPivot(content, new Vector2(posFromBottomLeft.x / content.rect.width, posFromBottomLeft.y / content.rect.height));
          }
          //pc input end
  
          if (Mathf.Abs(content.localScale.x - _currentZoom) > 0.001f)
              content.localScale = Vector3.Lerp(content.localScale, Vector3.one * _currentZoom, _zoomLerpSpeed * Time.deltaTime);
      }
  
      protected override void SetContentAnchoredPosition(Vector2 position)
      {
          if (_isPinching || blockPan) return;
          base.SetContentAnchoredPosition(position);
      }
  
      void OnPinchStart()
      {
          Vector2 pos1 = Input.touches[0].position;
          Vector2 pos2 = Input.touches[1].position;
  
          _startPinchDist = Distance(pos1, pos2) * content.localScale.x;
          _startPinchZoom = _currentZoom;
          _startPinchScreenPosition = (pos1 + pos2) / 2;
          RectTransformUtility.ScreenPointToLocalPointInRectangle(content, _startPinchScreenPosition, null, out _startPinchCenterPosition);
  
          Vector2 pivotPosition = new Vector3(content.pivot.x * content.rect.size.x, content.pivot.y * content.rect.size.y);
          Vector2 posFromBottomLeft = pivotPosition + _startPinchCenterPosition;
  
          SetPivot(content, new Vector2(posFromBottomLeft.x / content.rect.width, posFromBottomLeft.y / content.rect.height));
          blockPan = true;
      }
  
      void OnPinch()
      {
          float currentPinchDist = Distance(Input.touches[0].position, Input.touches[1].position) * content.localScale.x;
          _currentZoom = (currentPinchDist / _startPinchDist) * _startPinchZoom;
          _currentZoom = Mathf.Clamp(_currentZoom, _minZoom, _maxZoom);
      }
  
      float Distance(Vector2 pos1, Vector2 pos2)
      {
          RectTransformUtility.ScreenPointToLocalPointInRectangle(content, pos1, null, out pos1);
          RectTransformUtility.ScreenPointToLocalPointInRectangle(content, pos2, null, out pos2);
          return Vector2.Distance(pos1, pos2);
      }
  
      static void SetPivot(RectTransform rectTransform, Vector2 pivot)
      {
          if (rectTransform == null) return;
  
          Vector2 size = rectTransform.rect.size;
          Vector2 deltaPivot = rectTransform.pivot - pivot;
          Vector3 deltaPosition = new Vector3(deltaPivot.x * size.x, deltaPivot.y * size.y) * rectTransform.localScale.x;
          rectTransform.pivot = pivot;
          rectTransform.localPosition -= deltaPosition;
      }
  }