实现BMP图像的直方图，灰度的线性变换，灰度对数变换，伽玛变换，灰度阀值变换，分段线性变换，直方图均衡化，直方图规定化。(To achieve BMP image histogram, gray linear transformation, gray logarithmic transformation, gamma transform, gray threshold transformation, piecewise linear transformation, histogram equal