From 59af653d40acea599b6725fe2e3660c0a1c57687 Mon Sep 17 00:00:00 2001
From: mbahsomo <mbahsomo@gmail.com>
Date: Sun, 3 May 2026 00:24:14 +0000
Subject: [PATCH] Add opencv-4.6.md

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 opencv-4.6.md | 158 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 158 insertions(+)
 create mode 100644 opencv-4.6.md

diff --git a/opencv-4.6.md b/opencv-4.6.md
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+Di Ubuntu 26.04, repo resmi sudah pakai OpenCV lebih baru (≈4.10), jadi kalau kamu mau **OpenCV 4.6**, cara paling aman adalah **build manual dengan prefix terpisah** supaya tidak bentrok dengan versi sistem.
+
+Berikut setup yang **stabil + rapi + tidak konflik** 👇
+
+---
+
+# 🎯 Strategi yang benar
+
+* ❌ Jangan timpa `/usr` (punya apt)
+* ✅ Install ke lokasi khusus: `/opt/opencv-4.6`
+* ✅ Gunakan `PKG_CONFIG_PATH` untuk memilih versi
+
+---
+
+# 🚀 1. Install dependency
+
+```bash
+sudo apt update
+sudo apt install -y build-essential cmake git pkg-config
+```
+
+---
+
+# 📥 2. Download OpenCV 4.6
+
+```bash
+git clone https://github.com/opencv/opencv.git
+cd opencv
+git checkout 4.6.0
+mkdir build && cd build
+```
+
+---
+
+# ⚙️ 3. Konfigurasi minimal (ringan + stabil)
+
+## 👉 Profil cocok untuk Go / ArUco
+
+```bash
+cmake .. \
+-DCMAKE_BUILD_TYPE=Release \
+-DCMAKE_INSTALL_PREFIX=/opt/opencv-4.6 \
+-DBUILD_LIST=core,imgproc,imgcodecs,calib3d,aruco \
+-DBUILD_SHARED_LIBS=ON \
+-DWITH_IPP=OFF \
+-DWITH_TBB=OFF \
+-DWITH_OPENMP=ON \
+-DWITH_CUDA=OFF \
+-DWITH_OPENCL=OFF \
+-DWITH_FFMPEG=OFF \
+-DWITH_GSTREAMER=OFF \
+-DWITH_QT=OFF \
+-DWITH_GTK=OFF \
+-DBUILD_TESTS=OFF \
+-DBUILD_PERF_TESTS=OFF \
+-DBUILD_EXAMPLES=OFF \
+-DBUILD_JAVA=OFF \
+-DBUILD_opencv_python=OFF
+```
+
+---
+
+# 🔨 4. Build & install
+
+```bash
+make -j$(nproc)
+sudo make install
+sudo ldconfig
+```
+
+---
+
+# 🔗 5. Aktifkan OpenCV 4.6 (penting)
+
+## Temporary:
+
+```bash
+export PKG_CONFIG_PATH=/opt/opencv-4.6/lib/pkgconfig
+export LD_LIBRARY_PATH=/opt/opencv-4.6/lib:$LD_LIBRARY_PATH
+```
+
+## Permanen:
+
+```bash
+echo 'export PKG_CONFIG_PATH=/opt/opencv-4.6/lib/pkgconfig' >> ~/.bashrc
+echo 'export LD_LIBRARY_PATH=/opt/opencv-4.6/lib:$LD_LIBRARY_PATH' >> ~/.bashrc
+source ~/.bashrc
+```
+
+---
+
+# 🧪 6. Verifikasi
+
+```bash
+pkg-config --modversion opencv4
+```
+
+👉 Harus keluar:
+
+```
+4.6.0
+```
+
+---
+
+# 🚀 7. Build ulang Go / C++ kamu
+
+```bash
+go clean -cache -modcache -i -r
+go build -o aruco
+```
+
+atau C++:
+
+```bash
+g++ aruco.cpp -o aruco `pkg-config --cflags --libs opencv4`
+```
+
+---
+
+# ⚠️ Hal penting (biar tidak error lagi)
+
+* Jangan campur:
+
+  * `/usr/lib` (OpenCV 4.10 dari apt)
+  * `/opt/opencv-4.6` (manual)
+* Selalu set `PKG_CONFIG_PATH`
+* Selalu rebuild setelah ganti versi
+
+---
+
+# 🧠 Tips pro
+
+Kalau mau switch versi:
+
+```bash
+# pakai 4.6
+export PKG_CONFIG_PATH=/opt/opencv-4.6/lib/pkgconfig
+
+# balik ke system (4.10)
+export PKG_CONFIG_PATH=/usr/lib/x86_64-linux-gnu/pkgconfig
+```
+
+---
+
+# 🏁 Kesimpulan
+
+✔ Bisa install OpenCV 4.6 di Ubuntu 26.04
+✔ Jangan pakai apt → harus build manual
+✔ Gunakan prefix `/opt` biar clean
+✔ Aman dipakai bareng Go / GoCV
+
+---
+
+Kalau mau, saya bisa bantu:
+
+* bikin script otomatis install (1x jalan langsung beres)
+* atau buat Docker image Go + OpenCV 4.6 super ringan (production-ready)