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--- guides:opencv [2024/01/30 02:11] – created discord
+++ guides:opencv [2024/02/02 04:22] (current) – discord
@@ Line 1: / Line 1: @@
-Instructions for integrating OpenCV with Folk.
+//Original Author: Jacob Haip.
+Contributions welcome!//
+Instructions for integrating OpenCV with Folk. This guide involves a manual compilation set outside of folk, but the creation of the wrapper files and the compilation (via an TCL "exec" call) could also be moved within a folk program to completely encapsulate the code.
 . Install OpenCV
@@ Line 5: / Line 8: @@
    sudo apt-get install -y libopencv-dev
-. Create a C wrapper for the OpenCV functions you want to use
+. Create a C wrapper for the OpenCV functions you want to use. I saved these files in a new ~/folk/play/opencv folder.
 OpenCVWrapper.h
@@ Line 96: / Line 99: @@
 }
 </code>
+. Compile the wrapper
+   g++ -fPIC -shared OpenCVWrapper.cpp -o libopencvwrapper.so `pkg-config --cflags --libs opencv4`
+. Use the compiled libopencvwrapper.so and .h file in your folk C code
+<code tcl>
+set cc [c create]
+defineImageType $cc
+$cc cflags -I$::env(HOME)/folk/play/opencv
+$cc include <stdio.h>
+$cc include "OpenCVWrapper.h"
+if {[namespace exists ::Heap]} {
+    $cc import ::Heap::cc folkHeapAlloc as folkHeapAlloc
+    $cc import ::Heap::cc folkHeapFree as folkHeapFree
+} else {
+    $cc code { #define folkHeapAlloc malloc }
+    $cc code { #define folkHeapFree free }
+}
+$cc proc opencvAdaptiveThreshold {image_t img} image_t {
+    cv_image_t im2 = (cv_image_t) { .width = img.width, .height = img.height, .components = img.components, .bytesPerRow = img.bytesPerRow, .data = img.data };
+    cv_image_t r = myAdaptiveThreshold(im2);
+    image_t ret = (image_t) { .width = r.width, .height = r.height, .components = r.components, .bytesPerRow = r.bytesPerRow, .data = folkHeapAlloc(r.bytesPerRow * r.height) };
+    memcpy(ret.data, r.data, r.bytesPerRow * r.height);
+    return ret;
+}
+c loadlib $::env(HOME)/folk/play/opencv/libopencvwrapper.so
+$cc compile
+When $this has region /r/ {
+    Claim $this' has region [region move $r down 110%]
+}
+set ::opencvOldFrames [list]
+When $this' has camera slice /slice/ & $this has region /r/ {
+    set grayImg [opencvAdaptiveThreshold $slice]
+    set center [region centroid $r]
+    Wish to draw an image with center $center image $grayImg radians 0 scale 2
+    lappend ::opencvOldFrames $grayImg
+    if {[llength $::opencvOldFrames] >= 10} {
+        set ::opencvOldFrames [lassign $::opencvOldFrames oldestFrame]
+        image freeImage $oldestFrame
+    }
+}
+</code>
+{{:guides:opencv-threshold-example.jpeg?400|}}