diff --git a/src/pc/gui/main_window.py b/src/pc/gui/main_window.py
index 6c9b0a9..bd4fd57 100644
--- a/src/pc/gui/main_window.py
+++ b/src/pc/gui/main_window.py
@@ -328,7 +328,7 @@
         )
 
         self._spin_binary_thresh = QSpinBox()
-        self._spin_binary_thresh.setRange(10, 200)
+        self._spin_binary_thresh.setRange(0, 255)
         self._spin_binary_thresh.setValue(
             ip.binary_thresh,
         )
@@ -338,7 +338,7 @@
         )
 
         self._spin_open_size = QSpinBox()
-        self._spin_open_size.setRange(1, 31)
+        self._spin_open_size.setRange(1, 999)
         self._spin_open_size.setSingleStep(2)
         self._spin_open_size.setValue(ip.open_size)
         self._add_image_row(
@@ -347,7 +347,7 @@
         )
 
         self._spin_close_width = QSpinBox()
-        self._spin_close_width.setRange(1, 51)
+        self._spin_close_width.setRange(1, 999)
         self._spin_close_width.setSingleStep(2)
         self._spin_close_width.setValue(ip.close_width)
         self._add_image_row(
@@ -357,7 +357,7 @@
 
         # --- 案A/C: Black-hat ---
         self._spin_blackhat_ksize = QSpinBox()
-        self._spin_blackhat_ksize.setRange(11, 101)
+        self._spin_blackhat_ksize.setRange(1, 999)
         self._spin_blackhat_ksize.setSingleStep(2)
         self._spin_blackhat_ksize.setValue(
             ip.blackhat_ksize,
@@ -369,7 +369,7 @@
 
         # --- 案B: 背景除算 ---
         self._spin_bg_blur_ksize = QSpinBox()
-        self._spin_bg_blur_ksize.setRange(31, 201)
+        self._spin_bg_blur_ksize.setRange(1, 999)
         self._spin_bg_blur_ksize.setSingleStep(2)
         self._spin_bg_blur_ksize.setValue(
             ip.bg_blur_ksize,
@@ -381,7 +381,7 @@
 
         # --- 案B/C: 適応的閾値 ---
         self._spin_adaptive_block = QSpinBox()
-        self._spin_adaptive_block.setRange(11, 101)
+        self._spin_adaptive_block.setRange(3, 999)
         self._spin_adaptive_block.setSingleStep(2)
         self._spin_adaptive_block.setValue(
             ip.adaptive_block,
@@ -392,7 +392,7 @@
         )
 
         self._spin_adaptive_c = QSpinBox()
-        self._spin_adaptive_c.setRange(1, 30)
+        self._spin_adaptive_c.setRange(0, 255)
         self._spin_adaptive_c.setValue(ip.adaptive_c)
         self._add_image_row(
             "適応定数C:", self._spin_adaptive_c,
@@ -401,7 +401,7 @@
 
         # --- 案A/B/C: 後処理 ---
         self._spin_iso_close = QSpinBox()
-        self._spin_iso_close.setRange(1, 51)
+        self._spin_iso_close.setRange(1, 999)
         self._spin_iso_close.setSingleStep(2)
         self._spin_iso_close.setValue(
             ip.iso_close_size,
@@ -420,7 +420,7 @@
         )
 
         self._spin_min_line_width = QSpinBox()
-        self._spin_min_line_width.setRange(1, 20)
+        self._spin_min_line_width.setRange(1, 999)
         self._spin_min_line_width.setValue(
             ip.min_line_width,
         )
@@ -435,7 +435,7 @@
         }
 
         self._spin_median_ksize = QSpinBox()
-        self._spin_median_ksize.setRange(0, 31)
+        self._spin_median_ksize.setRange(0, 999)
         self._spin_median_ksize.setSingleStep(2)
         self._spin_median_ksize.setValue(ip.median_ksize)
         self._spin_median_ksize.setSpecialValueText(
@@ -465,7 +465,7 @@
 
         # --- 幅フィルタ（透視補正） ---
         self._spin_width_near = QSpinBox()
-        self._spin_width_near.setRange(0, 200)
+        self._spin_width_near.setRange(0, 9999)
         self._spin_width_near.setValue(ip.width_near)
         self._spin_width_near.setSpecialValueText("無効")
         self._add_image_row(
@@ -474,7 +474,7 @@
         )
 
         self._spin_width_far = QSpinBox()
-        self._spin_width_far.setRange(0, 200)
+        self._spin_width_far.setRange(0, 9999)
         self._spin_width_far.setValue(ip.width_far)
         self._spin_width_far.setSpecialValueText("無効")
         self._add_image_row(
@@ -492,7 +492,7 @@
 
         # --- 案D: 谷検出+追跡 ---
         self._spin_valley_gauss = QSpinBox()
-        self._spin_valley_gauss.setRange(3, 51)
+        self._spin_valley_gauss.setRange(3, 999)
         self._spin_valley_gauss.setSingleStep(2)
         self._spin_valley_gauss.setValue(
             ip.valley_gauss_ksize,
@@ -503,7 +503,7 @@
         )
 
         self._spin_valley_min_depth = QSpinBox()
-        self._spin_valley_min_depth.setRange(1, 100)
+        self._spin_valley_min_depth.setRange(1, 255)
         self._spin_valley_min_depth.setValue(
             ip.valley_min_depth,
         )
@@ -513,7 +513,7 @@
         )
 
         self._spin_valley_max_dev = QSpinBox()
-        self._spin_valley_max_dev.setRange(5, 200)
+        self._spin_valley_max_dev.setRange(1, 9999)
         self._spin_valley_max_dev.setValue(
             ip.valley_max_deviation,
         )
@@ -523,7 +523,7 @@
         )
 
         self._spin_valley_coast = QSpinBox()
-        self._spin_valley_coast.setRange(0, 10)
+        self._spin_valley_coast.setRange(0, 999)
         self._spin_valley_coast.setValue(
             ip.valley_coast_frames,
         )
@@ -1001,9 +1001,12 @@
         value: float, min_val: float,
         max_val: float, step: float,
     ) -> QDoubleSpinBox:
-        """パラメータ用の SpinBox を作成する"""
+        """パラメータ用の SpinBox を作成する
+
+        直接入力にも対応するため，範囲は広めに設定する
+        """
         spin = QDoubleSpinBox()
-        spin.setRange(min_val, max_val)
+        spin.setRange(min_val, 99999.0)
         spin.setSingleStep(step)
         spin.setDecimals(3)
         spin.setValue(value)