Pdfium image was blur

My image was blur in the pdfium rendering. When i multiplied the width and height with 4 , the output image was good quality. I don't know the exact way to get a quality image in pdfium rendering. i used the code

 IntPtr createdpages = FPDFBitmap_CreateEx(width  , height , 4, (IntPtr)p, width*4 );
                    uint background = 0xFFFFFFFF;
                    FPDFBitmap_FillRect(createdpages, 0, 0, width, height, background);
                    FPDF_RenderPageBitmap(createdpages, page, 0, 0, width, height, 0, FPDF.ANNOT);
                    FPDFBitmap_Destroy(createdpages);