代码里面设置像素为255，可结果为什么是205？
int lineByte=(m_nBitCount*m_imgWidth/8+3)/4*4; m_pImgDataOut=new unsigned char[lineByte*m_imgHeight]; int pixelByte=m_nBitCount/8; int i,j,k,t; for (i=1;i<m_imgHeight-1;i++) { for (j=1;j<m_imgWidth-1;j++) { for (k=0;k<pixelByte;k++) { t= 8* *(m_pImgData+i*lineByte+j*pixelByte+k) -1* *(m_pImgData+(i-1)*lineByte+j*pixelByte+k) -2**(m_pImgData+(i+1)*lineByte+j*pixelByte+k) -0* *(m_pImgData+i*lineByte+(j-1)*pixelByte+k) -0**(m_pImgData+i*lineByte+(j+1)*pixelByte+k) -0**(m_pImgData+(i+1)*lineByte+(j+1)*pixelByte+k) -0**(m_pImgData+(i-1)*lineByte+(j+1)*pixelByte+k) -0**(m_pImgData+(i+1)*lineByte+(j-1)*pixelByte+k) -0**(m_pImgData+(i-1)*lineByte+(j-1)*pixelByte+k); t=abs(t)+0.5; if(t>160) t=0; else t=255; *(m_pImgDataOut+i*lineByte+j*pixelByte+k)=t; } } }