ArcEngine中主要是用ILayerEffects接口对栅格图层的透明度、对比度、亮度进行调整，其中透明度的取值范围为0-100，对比度和亮度的取值范围为-100-100，代码如下：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using ESRI.ArcGIS.Carto;
using ESRI.ArcGIS.Controls;
using ESRI.ArcGIS.DataSourcesFile;
using ESRI.ArcGIS.DataSourcesGDB;
using ESRI.ArcGIS.DataSourcesRaster;
using ESRI.ArcGIS.Display;
using ESRI.ArcGIS.esriSystem;
using ESRI.ArcGIS.Geodatabase;
using ESRI.ArcGIS.Geometry;
using ESRI.ArcGIS.Output;
using ESRI.ArcGIS.SystemUI;

namespace WindowsFormsApplication1
{
    public partial class MainForm : Form
    {
        public MainForm()
        {
            InitializeComponent();
        }

        // 添加影像数据
        private void btnAddData_Click(object sender, EventArgs e)
        {
            OpenFileDialog openFileDialog = new OpenFileDialog();
            openFileDialog.Title = "选择栅格文件";
            openFileDialog.Filter = "TIFF(*.tif)|*.tif";
            openFileDialog.RestoreDirectory = true;
            if (openFileDialog.ShowDialog() == DialogResult.OK)
            {
                IWorkspaceFactory pWorkspaceFactory = new RasterWorkspaceFactory();
                IWorkspace pWorkspace = pWorkspaceFactory.OpenFromFile(System.IO.Path.GetDirectoryName(openFileDialog.FileName), 0);
                IRasterWorkspace pRasterWorkspace = pWorkspace as IRasterWorkspace;
                IRasterDataset pRasterDataset = pRasterWorkspace.OpenRasterDataset(System.IO.Path.GetFileName(openFileDialog.FileName));

                // 创建金字塔
                IRasterPyramid pRasterPyramid = pRasterDataset as IRasterPyramid;
                if (!pRasterPyramid.Present)
                {
                    pRasterPyramid.Create();
                }

                // 栅格图层
                IRasterLayer pRasterLayer = new RasterLayer();
                pRasterLayer.CreateFromDataset(pRasterDataset);
                ILayer pLayer = pRasterLayer as ILayer;

                // 刷新地图
                axMapControl1.AddLayer(pLayer, 0);
                axMapControl1.Refresh();
            }
        }

        // 调整透明度
        private void trackBar1_Scroll(object sender, EventArgs e)
        {
            IRasterLayer pRasterLayer = axMapControl1.get_Layer(0) as IRasterLayer;
            ILayerEffects pLayerEffects = pRasterLayer as ILayerEffects;
            pLayerEffects.Transparency = (short)trackBar1.Value;
            axMapControl1.ActiveView.Refresh();
        }

        // 调整对比度
        private void trackBar2_Scroll(object sender, EventArgs e)
        {
            IRasterLayer pRasterLayer = axMapControl1.get_Layer(0) as IRasterLayer;
            ILayerEffects pLayerEffects = pRasterLayer as ILayerEffects;
            pLayerEffects.Contrast = (short)trackBar2.Value;
            axMapControl1.ActiveView.Refresh();
        }

        // 调整亮度
        private void trackBar3_Scroll(object sender, EventArgs e)
        {
            IRasterLayer pRasterLayer = axMapControl1.get_Layer(0) as IRasterLayer;
            ILayerEffects pLayerEffects = pRasterLayer as ILayerEffects;
            pLayerEffects.Brightness = (short)trackBar3.Value;
            axMapControl1.ActiveView.Refresh();
        }
    }
}

结果如下图：