Port hist_find_ndim

vips/arithmetic.c

@@ -28,6 +28,13 @@ int average(VipsImage *in, double *out) {
 	return vips_avg(in, out, NULL);
 }
 
+int maxpos(VipsImage *in, double *out, int *x, int *y) {
+  return vips_max(in, out, "x", x, "y", y, NULL);
+}
+
+int minpos(VipsImage *in, double *out, int *x, int *y) {
+  return vips_min(in, out, "x", x, "y", y, NULL);
+}
 int find_trim(VipsImage *in, int *left, int *top, int *width, int *height,
               double threshold, double r, double g, double b) {
 
@@ -58,6 +65,10 @@ int hist_find(VipsImage *in, VipsImage **out) {
   return vips_hist_find(in, out, NULL);
 }
 
+int hist_find_ndim(VipsImage *in, VipsImage **out, int bins) {
+  return vips_hist_find_ndim(in, out, "bins", bins, NULL);
+}
+
 int hist_cum(VipsImage *in, VipsImage **out) {
   return vips_hist_cum(in, out, NULL);
 }

vips/arithmetic.go

@@ -139,6 +139,44 @@ func vipsHistFind(in *C.VipsImage) (*C.VipsImage, error) {
 	return out, nil
 }
 
+// https://www.libvips.org/API/current/libvips-arithmetic.html#vips-hist-find-ndim
+func vipsHistFindNdim(in *C.VipsImage, bins int) (*C.VipsImage, error) {
+	incOpCounter("histFindNdim")
+	var out *C.VipsImage
+
+	if err := C.hist_find_ndim(in, &out, C.int(bins)); err != 0 {
+		return nil, handleImageError(out)
+	}
+
+	return out, nil
+}
+
+// https://www.libvips.org/API/current/libvips-arithmetic.html#vips-max
+func vipsMax(in *C.VipsImage) (int, int, error) {
+	incOpCounter("max")
+	var out C.double
+	var x, y C.int
+
+	if err := C.maxpos(in, &out, &x, &y); err != 0 {
+		return -1, -1, handleVipsError()
+	}
+
+	return int(x), int(y), nil
+}
+
+// https://www.libvips.org/API/current/libvips-arithmetic.html#vips-min
+func vipsMin(in *C.VipsImage) (int, int, error) {
+	incOpCounter("min")
+	var out C.double
+	var x, y C.int
+
+	if err := C.maxpos(in, &out, &x, &y); err != 0 {
+		return -1, -1, handleVipsError()
+	}
+
+	return int(x), int(y), nil
+}
+
 // https://www.libvips.org/API/current/libvips-histogram.html#vips-hist-norm
 func vipsHistNorm(in *C.VipsImage) (*C.VipsImage, error) {
 	incOpCounter("histNorm")

vips/arithmetic.h

@@ -14,7 +14,10 @@ int find_trim(VipsImage *in, int *left, int *top, int *width, int *height,
               double threshold, double r, double g, double b);
 int getpoint(VipsImage *in, double **vector, int n, int x, int y);
 int stats(VipsImage *in, VipsImage **out);
+int maxpos(VipsImage *in, double *out, int *x, int *y);
+int minpos(VipsImage *in, double *out, int *x, int *y);
 int hist_find(VipsImage *in, VipsImage **out);
+int hist_find_ndim(VipsImage *in, VipsImage **out, int bins);
 int hist_cum(VipsImage *in, VipsImage **out);
 int hist_norm(VipsImage *in, VipsImage **out);
 int hist_entropy(VipsImage *in, double *out);

vips/image.go

@@ -1708,7 +1708,7 @@ func (r *ImageRef) Stats() error {
 	return nil
 }
 
-// HistogramFind find the histogram the image.
+// HistogramFind find the histogram of the image.
 // Find the histogram for all bands (producing a one-band histogram).
 // char and uchar images are cast to uchar before histogramming, all other image types are cast to ushort.
 func (r *ImageRef) HistogramFind() error {
@@ -1720,6 +1720,26 @@ func (r *ImageRef) HistogramFind() error {
 	return nil
 }
 
+// Make a one, two or three dimensional histogram of a 1, 2 or 3 band image. Divide each axis into `bins` bins .. ie. output is 1 x bins, bins x bins, or bins x bins x bins bands. bins defaults to 10.
+func (r *ImageRef) HistogramFindNdim(bins int) error {
+	out, err := vipsHistFindNdim(r.image, bins)
+	if err != nil {
+		return err
+	}
+	r.setImage(out)
+	return nil
+}
+
+// This operation finds the maximum value in an image.
+func (r *ImageRef) MaxPos() (x, y int, err error) {
+	return vipsMax(r.image)
+}
+
+// This operation finds the maximum value in an image.
+func (r *ImageRef) MinPos() (x, y int, err error) {
+	return vipsMin(r.image)
+}
+
 // HistogramCumulative form cumulative histogram.
 func (r *ImageRef) HistogramCumulative() error {
 	out, err := vipsHistCum(r.image)