resolve #360, fix axis parse issue when add / get pictures;

typo fixed and go test updated

excelize_test.go

@@ -819,8 +819,8 @@ func TestGetPicture(t *testing.T) {
 	}
 
 	file, raw := xlsx.GetPicture("Sheet1", "F21")
-	if !assert.NotEmpty(t, file) || !assert.NotEmpty(t, raw) ||
+	if !assert.NotEmpty(t, filepath.Join("test", file)) || !assert.NotEmpty(t, raw) ||
-		!assert.NoError(t, ioutil.WriteFile(file, raw, 0644)) {
+		!assert.NoError(t, ioutil.WriteFile(filepath.Join("test", file), raw, 0644)) {
 
 		t.FailNow()
 	}
@@ -851,8 +851,8 @@ func TestGetPicture(t *testing.T) {
 	}
 
 	file, raw = xlsx.GetPicture("Sheet1", "F21")
-	if !assert.NotEmpty(t, file) || !assert.NotEmpty(t, raw) ||
+	if !assert.NotEmpty(t, filepath.Join("test", file)) || !assert.NotEmpty(t, raw) ||
-		!assert.NoError(t, ioutil.WriteFile(file, raw, 0644)) {
+		!assert.NoError(t, ioutil.WriteFile(filepath.Join("test", file), raw, 0644)) {
 
 		t.FailNow()
 	}

picture.go

@@ -266,6 +266,8 @@ func (f *File) addDrawingPicture(sheet, drawingXML, cell, file string, width, he
 	col, row := MustCellNameToCoordinates(cell)
 	width = int(float64(width) * formatSet.XScale)
 	height = int(float64(height) * formatSet.YScale)
+	col--
+	row--
 	colStart, rowStart, _, _, colEnd, rowEnd, x2, y2 :=
 		f.positionObjectPixels(sheet, col, row, formatSet.OffsetX, formatSet.OffsetY, width, height)
 	content, cNvPrID := f.drawingParser(drawingXML)
@@ -469,7 +471,8 @@ func (f *File) getSheetRelationshipsTargetByID(sheet, rID string) string {
 //
 func (f *File) GetPicture(sheet, cell string) (string, []byte) {
 	col, row := MustCellNameToCoordinates(cell)
-
+	col--
+	row--
 	xlsx := f.workSheetReader(sheet)
 	if xlsx.Drawing == nil {
 		return "", []byte{}

sheet.go

@@ -1032,7 +1032,8 @@ func (f *File) workSheetRelsWriter() {
 	}
 }
 
-// fillSheetData fill missing row and cell XML data to made it continous from first cell [1, 1] to last cell [col, row]
+// fillSheetData fill missing row and cell XML data to made it continuous from
+// first cell [1, 1] to last cell [col, row]
 func prepareSheetXML(xlsx *xlsxWorksheet, col int, row int) {
 	rowCount := len(xlsx.SheetData.Row)
 	if rowCount < row {