From 5176b0b6b7e54b956f9aa7df11f59d342e7510b1 Mon Sep 17 00:00:00 2001
From: Peter Williams <peter.williams@papercut.com>
Date: Fri, 5 May 2017 18:16:21 +1000
Subject: [PATCH] Allow xobject image modification that preserves unchanged
 parts of original xobject

---
 pdf/model/xobject.go | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/pdf/model/xobject.go b/pdf/model/xobject.go
index 90cef5a0..90814aa5 100644
--- a/pdf/model/xobject.go
+++ b/pdf/model/xobject.go
@@ -245,7 +245,13 @@ func NewXObjectImage() *XObjectImage {
 // Creates a new XObject Image from an image object with default options.
 // If encoder is nil, uses raw encoding (none).
 func NewXObjectImageFromImage(name PdfObjectName, img *Image, cs PdfColorspace, encoder StreamEncoder) (*XObjectImage, error) {
-	xobj := NewXObjectImage()
+	baseXObj := NewXObjectImage()
+	return UpdateXObjectImageFromImage(baseXObj, name, img, cs, encoder)
+}
+
+func UpdateXObjectImageFromImage(baseXObj *XObjectImage, name PdfObjectName, img *Image, cs PdfColorspace, encoder StreamEncoder) (*XObjectImage, error) {
+	dupObj := *baseXObj
+	xobj := &dupObj
 
 	if encoder == nil {
 		encoder = NewRawEncoder()