图片位深的获取

大概思路：图像的位深度，就存储在文件的byte数组里，找到位置，就能获取到。

//获取bmp图片位深

int getBmpBitDepth(constQString&imagePath){QFile imageFile(imagePath);if(!imageFile.open(QIODevice::ReadWrite)){return -1;}QByteArray ba =imageFile.readAll();int bitsPerPixel =(ba[28]& 0xff)| (ba[29]& 0xff)<< 8;printf("Bmpdepth=%d\n",bitsPerPixel);imageFile.close();return bitsPerPixel;}//获取png图片位深int getPngBitDepth(constQString&imagePath){QFile imageFile(imagePath);if(!imageFile.open(QIODevice::ReadWrite)){return -1;}QByteArray ba =imageFile.readAll();int bitsPerPixel =ba[24]& 0xff;if((ba[25]& 0xff)== 2){bitsPerPixel*= 3;}else if((ba[25]& 0xff)== 6){bitsPerPixel*= 4;}printf("Pngdepth=%d\n",bitsPerPixel);imageFile.close();return bitsPerPixel;}//获取Jpeg图片位深int getJpegBitDepth(constQString&imagePath){QFile imageFile(imagePath);if(!imageFile.open(QIODevice::ReadWrite)){return -1;}QByteArray ba =imageFile.readAll();int i =2;int bitsPerPixel=0;while(true){int marker =(ba[i] &0xff)<< 8| (ba[i+ 1]& 0xff);int size =(ba[i +2]& 0xff)<< 8| (ba[i+ 3]& 0xff);if(marker >=0xffc0&& marker<= 0xffcf&& marker!= 0xffc4&&marker !=0xffc8){bitsPerPixel= (ba[i+ 4]& 0xff)* (ba[i+ 9]& 0xff);break;}else{i+= size+ 2;}}printf("Jpegdepth=%d\n",bitsPerPixel);imageFile.close();return bitsPerPixel;}//获取gif位深gif：获取到是第一张图片的位深度，对于那种多张图片组成的动态图的位深度，应该是所有图片中位深度最高的那个才是最终的值。  int bitsPerPixel=(bytes[10] & 0x07) + 1;  int main(){QString path_0("D:\\workspace\\aaa.bmp");int bmpDepth =getBmpBitDepth(path_0);QString path_1("D:\\workspace\\tray.png");int pngDepth =getPngBitDepth(path_1);QString path_2("D:\\workspace\\1111.jpg");int jpegDepth =getJpegBitDepth(path_2);}