通过Office自带的类库word文档中插入图片，图片大小的单位为磅
而文档中，图片的大小已经固定，为CM。
实际工作中，首先将图片插入到word中，根据目前的大小，计算转换为目标大小的比率，将长宽按照目标大小进行缩放即可。
msword.InlineShape spa = oOperateDoc.Tables[oOperateDoc.Tables.Count].Cell(1, 1).Range.InlineShapes.AddPicture(jietuA);
float yuanwidth = spa.Width;
float yuanheidht = spa.Height;
double bilv = GetChangepicSizeRation(yuanwidth,yuanheidht, targetW, targetH);
spa.Width = (float)(yuanwidth * bilv);
spa.Height = (float)(yuanheidht * bilv);
private double GetChangepicSizeRation(double width_pt, double height_pt, double targetWidthCM, double targetHeightCM)
{
//CM转pt
double p = 0.03527;// 0.03759; //1pt=0.3759mm
double TargetWdithPt = targetWidthCM / p;
double TargetHeightPt = targetHeightCM / p;
double[] bilv = new double[2];
bilv[0] = TargetWdithPt / width_pt;
bilv[1] = TargetHeightPt / height_pt;
return (bilv[0] > bilv[1] ? bilv[1] : bilv[0]);
}