added immultiread support

imgcodecs.cpp

@@ -1,3 +1,4 @@
+#include <stdlib.h>
 #include "imgcodecs.h"
 
 // Image
@@ -6,6 +7,38 @@ Mat Image_IMRead(const char* filename, int flags) {
     return new cv::Mat(img);
 }
 
+Mats Image_IMReadMulti(const char* filename, int flags) {
+    std::vector<cv::Mat> dst;
+    Mats m = Mats();
+
+    bool b = cv::imreadmulti(filename, dst, flags);
+    if (b) {
+        m.mats = new Mat[dst.size()];
+        for (size_t i = 0; i < dst.size(); ++i) {
+            m.mats[i] = new cv::Mat(dst[i]);
+        }
+        m.length = (int)dst.size();        
+    }
+
+    return m;
+}
+
+Mats Image_IMReadMulti_WithParams(const char* filename, int start, int count, int flags) {
+    std::vector<cv::Mat> dst;
+    auto m = Mats();
+
+    auto b = cv::imreadmulti(filename, dst, start, count, flags);
+    if (b) {
+        m.mats = new Mat[dst.size()];
+        for (size_t i = 0; i < dst.size(); ++i) {
+            m.mats[i] = new cv::Mat(dst[i]);
+        }
+        m.length = (int)dst.size();        
+    }
+
+    return m;
+}
+
 
 bool Image_IMWrite(const char* filename, Mat img) {
     return cv::imwrite(filename, *img);

imgcodecs.go

@@ -142,6 +142,58 @@ func IMRead(name string, flags IMReadFlag) Mat {
 	return newMat(C.Image_IMRead(cName, C.int(flags)))
 }
 
+// IMReadMulti reads multi-page image from a file into a []Mat.
+// The flags param is one of the IMReadFlag flags.
+// If the image cannot be read (because of missing file, improper permissions,
+// unsupported or invalid format), the function returns an empty []Mat.
+//
+// For further details, please see:
+// https://docs.opencv.org/4.x/d4/da8/group__imgcodecs.html#gaaeb5e219c706fd6aa1ec6cf17b172080
+func IMReadMulti(name string, flags IMReadFlag) []Mat {
+	var mats []Mat
+	multiRead := C.struct_Mats{}
+
+	cName := C.CString(name)
+	defer C.free(unsafe.Pointer(cName))
+
+	multiRead = C.Image_IMReadMulti(cName, C.int(flags))
+	defer C.Mats_Close(multiRead)
+
+	if multiRead.length > C.int(0) {
+		mats = make([]Mat, multiRead.length)
+		for i := 0; i < int(multiRead.length); i++ {
+			mats[i].p = C.Mats_get(multiRead, C.int(i))
+		}
+	}
+	return mats
+}
+
+// IMReadMulti reads multi-page image from a file into a []Mat.
+// The flags param is one of the IMReadFlag flags.
+// If the image cannot be read (because of missing file, improper permissions,
+// unsupported or invalid format), the function returns an empty []Mat.
+//
+// For further details, please see:
+// https://docs.opencv.org/4.x/d4/da8/group__imgcodecs.html#ga55e88dc40b65807cfbe2c62d27f7fdf9
+func IMReadMulti_WithParams(name string, start int, count int, flags IMReadFlag) []Mat {
+	var mats []Mat
+	multiRead := C.struct_Mats{}
+
+	cName := C.CString(name)
+	defer C.free(unsafe.Pointer(cName))
+
+	multiRead = C.Image_IMReadMulti_WithParams(cName, C.int(start), C.int(count), C.int(flags))
+	defer C.Mats_Close(multiRead)
+
+	if multiRead.length > C.int(0) {
+		mats = make([]Mat, multiRead.length)
+		for i := 0; i < int(multiRead.length); i++ {
+			mats[i].p = C.Mats_get(multiRead, C.int(i))
+		}
+	}
+	return mats
+}
+
 // IMWrite writes a Mat to an image file.
 //
 // For further details, please see:

imgcodecs.h

@@ -11,6 +11,8 @@ extern "C" {
 #include "core.h"
 
 Mat Image_IMRead(const char* filename, int flags);
+Mats Image_IMReadMulti(const char* filename, int flags);
+Mats Image_IMReadMulti_WithParams(const char* filename, int start, int count, int flags);
 bool Image_IMWrite(const char* filename, Mat img);
 bool Image_IMWrite_WithParams(const char* filename, Mat img, IntVector params);
 void Image_IMEncode(const char* fileExt, Mat img, void* vector);

imgcodecs_test.go

@@ -184,3 +184,27 @@ func TestIMDecodeWebp(t *testing.T) {
 	dec.Close()
 
 }
+
+func TestIMReadMulti(t *testing.T) {
+
+	mats := IMReadMulti("images/multipage.tif", IMReadAnyColor)
+
+	for i, page := range mats {
+		if page.Empty() {
+			t.Errorf("page %d empty", i)
+		}
+	}
+
+}
+
+func TestIMReadMulti_WithParams(t *testing.T) {
+
+	mats := IMReadMulti_WithParams("images/multipage.tif", 2, 3, IMReadAnyColor)
+
+	for i, page := range mats {
+		if page.Empty() {
+			t.Errorf("page %d empty", i)
+		}
+	}
+
+}