c# - Edge of the image is cutted out when conver DIBto ImageSource -

i use below code convert dib scanner twain bitmapsource, found edge of image cutted off. image size different source image. there thing wrong in below code when handel image?

/// <summary> /// managed bitmapsource dib provided low level windows hadle  /// /// notes: /// data copied source windows handle can saftely discarded /// when bitmapsource in use. ///  /// subset of possible dib forrmats supported. ///  /// </summary> /// <param name="dibhandle"></param> /// <returns>a copy of image in managed bitmapsource </returns> ///  public static bitmapsource formhdib(intptr dibhandle) {     bitmapsource bs = null;     intptr bmpptr = intptr.zero;     bool flip = true; // vertivcally flip image      try {         bmpptr = win32.globallock(dibhandle);         win32.bitmapinfoheader bmi = new win32.bitmapinfoheader();         marshal.ptrtostructure(bmpptr, bmi);          if (bmi.bisizeimage == 0)             bmi.bisizeimage = (uint)(((((bmi.biwidth * bmi.bibitcount) + 31) & ~31) >> 3) * bmi.biheight);          int palettsize = 0;          if (bmi.biclrused != 0)             throw new notsupportedexception("dibtobitmap: dib pallet not supported");          // pointer beginning of bitmap bits         intptr pixptr = (intptr)((int)bmpptr + bmi.bisize + palettsize);          // define parameters used create bitmapsource.         pixelformat pf = pixelformats.default;         switch (bmi.bibitcount) {             case 32:                 pf = pixelformats.bgr32;                 break;             case 24:                 pf = pixelformats.bgr24;                 break;             case 8:                 pf = pixelformats.gray8;                 break;             case 1:                 pf = pixelformats.blackwhite;                 break;             default:   // not supported                 throw new notsupportedexception("dibtobitmap: can't determine picture format (bibitcount=" + bmi.bibitcount + ")");             // break;         }         int width = bmi.biwidth;         int height = bmi.biheight;         int stride = (int)(bmi.bisizeimage / height);         byte[] imagebytes = new byte[stride * height];          //debug: initialize image random data.         //random value = new random();         //value.nextbytes(rawimage);          if (flip) {             (int = 0, j = 0, k = (height - 1) * stride; < height; i++, j += stride, k -= stride)                 marshal.copy(((intptr)((int)pixptr + j)), imagebytes, k, stride);         } else {             marshal.copy(pixptr, imagebytes, 0, imagebytes.length);         }          int xdpi = (int)math.round(bmi.bixpelspermeter * 2.54 / 100); // pels per meter dots per inch         int ydpi = (int)math.round(bmi.biypelspermeter * 2.54 / 100);          // create bitmapsource.         bs = bitmapsource.create(width, height, xdpi, ydpi, pf, null, imagebytes, stride);         win32.globalunlock(pixptr);         win32.globalfree(pixptr);         pixptr = intptr.zero;         imagebytes = null;         bmi = null;     } catch (exception ex) {         //string msg = ex.message;     }     {         // cleanup         if (bmpptr != intptr.zero) { // locked sucsessfully             win32.globalunlock(dibhandle);         }     }     win32.globalunlock(bmpptr);     win32.globalfree(bmpptr);     bmpptr = intptr.zero;      return bs; } 

this code here.

i find root reason now, it's caused wrong twain setting. set edge padding nothing solve problem.