Okay, decided on something for images. Let's try this.

darwin/CMakeLists.txt

@@ -21,6 +21,7 @@ list(APPEND _LIBUI_SOURCES
 	darwin/form.m
 	darwin/grid.m
 	darwin/group.m
+	darwin/image.m
 	darwin/label.m
 	darwin/main.m
 	darwin/map.m

darwin/image.m

@@ -0,0 +1,48 @@
+// 25 june 2016
+#import "uipriv_darwin.h"
+
+struct uiImage {
+	NSImage *i;
+	NSSize size;
+};
+
+uiImage *uiNewImage(double width, double height)
+{
+	uiImage *i;
+
+	i = uiNew(uiImage);
+	i->size = NSMakeSize(width, height);
+	i->i = [[NSImage alloc] initWithSize:i->size];
+	return i;
+}
+
+void uiFreeImage(uiImage *i)
+{
+	[i->i release];
+	uiFree(i);
+}
+
+void uiImageAppend(uiImage *i, void *pixels, int pixelWidth, int pixelHeight, int pixelStride)
+{
+	NSBitmapImageRep *repCalibrated, *repsRGB;
+	char *pix[1];
+
+	pix[0] = (char *) pixels;
+	repCalibrated = [[NSBitmapImageRep alloc] initWithBitmapDataPlanes:pix
+		pixelsWide:pixelWidth
+		pixelsHigh:pixelHeight
+		bitsPerSample:8
+		samplesPerPixel:4
+		hasAlpha:YES
+		isPlanar:NO
+		colorSpaceName:NSCalibratedRGBColorSpace
+		bitmapFormat:0
+		bytesPerRow:pixelStride
+		bitsPerPixel:32];
+	repsRGB = [repCalibrated bitmapImageRepByRetaggingWithColorSpace:[NSColorSpace sRGBColorSpace]];
+	[repCalibrated release];
+
+	[i->i addRepresentation:repsRGB];
+	[repsRGB setSize:i->size];
+	[repsRGB release];
+}

uitable.h

@@ -1,6 +1,12 @@
 // 20 june 2016
 // kept in a separate file for now
 
+typedef struct uiImage uiImage;
+
+_UI_EXTERN uiImage *uiNewImage(double width, double height);
+_UI_EXTERN void uiFreeImage(uiImage *i);
+_UI_EXTERN void uiImageAppend(uiImage *i, void *pixels, int pixelWidth, int pixelHeight, int pixelStride);
+
 typedef struct uiTableModel uiTableModel;
 typedef struct uiTableModelHandler uiTableModelHandler;