From 5e0cf451eaf7a962dac4a30a1c8ffa2007691713 Mon Sep 17 00:00:00 2001
From: Pierre-Yves Nicolas <6371790+pynicolas@users.noreply.github.com>
Date: Tue, 1 Jul 2025 21:24:10 +0200
Subject: [PATCH] Avoid detecting very small quadrilaterals

---
 app/src/main/java/org/mydomain/myscan/DocumentDetection.kt | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/app/src/main/java/org/mydomain/myscan/DocumentDetection.kt b/app/src/main/java/org/mydomain/myscan/DocumentDetection.kt
index 3962389..0adab1f 100644
--- a/app/src/main/java/org/mydomain/myscan/DocumentDetection.kt
+++ b/app/src/main/java/org/mydomain/myscan/DocumentDetection.kt
@@ -27,7 +27,7 @@ import kotlin.math.abs
 import kotlin.math.max
 import kotlin.math.sqrt
 
-fun detectDocumentQuad(mask: Bitmap): Quad? {
+fun detectDocumentQuad(mask: Bitmap, minQuadAreaRatio: Double = 0.02): Quad? {
     val mat = Mat()
     Utils.bitmapToMat(mask, mat)
 
@@ -62,6 +62,10 @@ fun detectDocumentQuad(mask: Bitmap): Quad? {
         }
     }
 
+    if (maxArea < mask.width * mask.height * minQuadAreaRatio) {
+        return null
+    }
+
     val vertices = biggest?.toList()?.map { Point(it.x.toInt(), it.y.toInt()) }
     return createQuad(vertices)
 }