diff --git a/src/steps/rulerStep.tsx b/src/steps/rulerStep.tsx
index 7cb193738158ee587898d57c3b875e26898b8050..5eb2aafebceb02d1a992b5811a6b194ad6aaa723 100644
--- a/src/steps/rulerStep.tsx
+++ b/src/steps/rulerStep.tsx
@@ -1,12 +1,15 @@
 import {Step, StepProps, StepState} from "./step";
 import * as React from "react";
-import {Alert, Button} from "react-bootstrap";
+import {Alert, Button, Form, InputGroup} from "react-bootstrap";
+import {DEBUG_MODE} from "../lab";
 
 /**
  * Etape de placement de la règle
  */
 export class RulerStep extends Step<StepState> {
 
+    private rescaleInputRef = React.createRef<HTMLInputElement>();
+
     public constructor(props : StepProps) {
         super(props, { active: false, activable : false });
     }
@@ -28,13 +31,32 @@ export class RulerStep extends Step<StepState> {
         this.props.lab.zoomIn(this.props.lab.data.rulerCoords.bounds().center);
     }
 
+    private rescale() {
+        let ppcm = Number.parseFloat(this.rescaleInputRef.current.value);
+        let rulerCoords = this.props.lab.data.rulerCoords;
+        rulerCoords.end = rulerCoords.start.add(new paper.Point(ppcm * this.props.lab.data.rulerTickCount, 0));
+        this.props.lab.ruler.refresh();
+    }
+
     render() : React.ReactNode {
         return <div>
             <div>
                 <Alert show={!this.state.activable} variant="warning" className={"p-1"}>Veuillez charger une photo.</Alert>
                 <p>Positionnez la règle sur la photo. La règle doit couvrir 10 cm.</p>
                 <Alert variant={"light"} className={"p-2"}><i className="ms-1 me-1 fa-solid fa-circle-info"></i> Appuyez ici <Button disabled={!this.state.active} onClick={this.zoomOnRuler.bind(this)} size={"sm"}><i className={"fa-solid fa-magnifying-glass-location"}></i></Button> pour placer la règle avec précision.</Alert>
-                <Button variant={"success"} disabled={!this.state.active} onClick={this.terminate.bind(this)}>Terminé !</Button>
+                <div className={"d-flex flex-row"}>
+                    <Button className={"col-3"} variant={"success"} disabled={!this.state.active} onClick={this.terminate.bind(this)}>Terminé&nbsp;!</Button>
+                    {DEBUG_MODE ?
+                        <>
+                            <InputGroup className={"ms-2"}>
+                                <Form.Control defaultValue={100} ref={this.rescaleInputRef} disabled={!this.state.active} type={"text"} aria-describedby="aria-describe-rescale"/>
+                                <InputGroup.Text id="aria-describe-rescale">px/cm</InputGroup.Text>
+                            </InputGroup>
+                            <Button className={"col-3"} variant={"danger"} disabled={!this.state.active} onClick={this.rescale.bind(this)}><i className="fa-solid fa-bug"></i>&nbsp;Rescale</Button>
+                        </>
+                        : <></>
+                    }
+                </div>
             </div>
         </div>
     }