多媒体作业 实验报告.doc

太原工业学院计算机工程系实 验 报 告姓名学号实验编号实验名称图片压缩课程名称多媒体技术教材多媒体技术应用1 实验目的做一个可以实现图像的压缩的工具。2 实验内容编程实现一个图像工具，可以打开原图像，在此基础上可以进行图像的压缩。3 实验步骤（附录源程序及效果图）（1） 首先用showImage（String imagename）方法创建一个图像监听器，并获得所选择的图像文件，然后创建图像缓冲区并显示。（2） 图像读至缓冲区，然后调用图片压缩方法对图像进行压缩。代码：Private Sub Command2_Click()On Error GoTo err1CommonDialog2.Action = 2Open CommonDialog2.FileName For Binary As #2Open CommonDialog1.FileName For Binary As #1Picture2.ClsDim bmpGeshi1 As Byte 。判断是不是BMP图片Dim bmpGeshi2 As ByteGet #1, 1, bmpGeshi1Get #1, 2, bmpGeshi2If bmpGeshi1 = 66 And bmpGeshi2 = 77 Then Picture2.Print BMPElse Picture2.Print 格式错误 Close #1 Exit SubEnd IfDim geShi As Byte 。判断BMP图片位数Get #1, &H1C + 1, geShiIf geShi = 24 Then Picture2.Print 24位Else Picture2.Print 文件是; geShi; 位格式不支持,请打开24位格式的BMP Close #1 Exit SubEnd IfPicture3.Picture = LoadPicture()Dim Kuan As Long 。找到图片高、宽Dim Gao As LongGet #1, &H12 + 1, KuanGet #1, &H16 + 1, GaoPicture2.Print 图像大小:宽; Kuan; 高; GaoDim BS As StringBS = B8Put #2, 1, BSPut #2, 2, 8Put #2, 3, KuanPut #2, 7, Gaoput #2,11,Picture3.Picture = LoadPicture()Dim pos As Long 文件中点的指针Dim cha As Integer 行末尾填充的字节数cha = Abs(Kuan * 3) Mod 4 - 4) Mod 4Picture2.Print 行末尾多余的字节; chapos = &H36 + 1Dim Pos8 As LongPos8 = 11Dim IX As Long 用于描出点的坐标Dim IY As Long 用于描出点的坐标Dim yanseRed As Byte 存红色的值Dim yanseGreen As Byte 存绿色的值Dim yanseBlue As Byte 存蓝色的值Dim endYanse As ByteDim endR As ByteDim endG As ByteDim endB As ByteDim yanseRed8 As Byte 存红色的值Dim yanseGreen8 As Byte 存绿色的值Dim yanseBlue8 As Byte 存蓝色的值For IY = Gao - 1 To 0 Step -1 y行 。描点For IX = 0 To Kuan - 1 x列 Get #1, pos, yanseBlue 得到颜色 Get #1, pos + 1, yanseGreen 得到颜色 Get #1, pos + 2, yanseRed 得到颜色 Picture1.PSet (IX, IY), RGB(yanseRed, yanseGreen, yanseBlue)Select Case yanseRedCase 0 To 41endR = 0Case 42 To 84endR = 1Case 85 To 127endR = 2Case 128 To 170endR = 3Case 171 To 213endR = 4Case 214 To 255endR = 5End SelectSelect Case yanseGreenCase 0 To 41endG = 0Case 42 To 84endG = 1Case 85 To 127endG = 2Case 128 To 170endG = 3Case 171 To 213endG = 4Case 214 To 255endG = 5End SelectSelect Case yanseBlueCase 0 To 41endB = 0Case 42 To 84endB = 1Case 85 To 127endB = 2Case 128 To 170endB = 3Case 171 To 213endB = 4Case 214 To 255endB = 5End SelectPicture3.PSet (IX, IY), RGB(endR * 42, endG * 42, endB * 42)endYanse = endR * 6 * 6 + endG * 6 + endBPut #2, Pos8, endYanse pos = pos + 3 开始读下一个像素 Pos8 = Pos8 + 1Next IX pos = pos + cha 描到了行末尾，则跳过不要的字节 Pos8 = Pos8 + chaNext IYClose #1 正常时关闭文件Close #2Exit Suberr1: 错误处理If Err = 32755 Then Exit Sub 打开文件对话框点取消时，发生32755错误错误Picture2.Print 发生错误; Err=; ErrClose #1 有错误时关闭文件Close #2Exit SubEnd SubPrivate Sub Command1_Click()On Error GoTo aaaPicture2.ClsCommonDialog1.Action = 1Picture1.Picture = LoadPicture()Picture1.Picture = LoadPicture(CommonDialog1.FileName)Command2.Enabled = TrueExit Subaaa:If Err = 32755 Then Exit Sub 打开文件对话框点取消时，发生32755错误错误Picture2.Print 图片格式不支持Command2.Enabled = FalseExit SubEnd SubPrivate Sub Command3_Click()On Error GoTo err1Picture2.ClsCommonDialog3.Action = 1Open CommonDialog3.FileName For Binary As #3Picture2.ClsDim bmp8Geshi1 As Byte 。判断是不是BMP8图片Dim bmp8Geshi2 As ByteGet #3, 1, bmp8Geshi1Get #3, 2, bmp8Geshi2If bmp8Geshi1 = &H42 And bmp8Geshi2 = &H38 Then Picture2.Print BMP8Else Picture2.Print 格式错误 Close #1 Exit SubEnd IfPicture3.Picture = LoadPicture()Dim Kuan8 As Long 。找到图片高、宽Dim Gao8 As LongGet #3, 3, Kuan8Get #3, 7, Gao8Picture2.Print 8位图像大小:宽; Kuan8; 高; Gao8Dim cha As Integercha = Abs(Kuan8 * 3) Mod 4 - 4) Mod 4Dim IX As Long 用于描出点的坐标Dim IY As Long 用于描出点的坐标Dim yanseRed8 As Byte 存红色的值Dim yanseGreen8 As Byte 存绿色的值Dim yanseBlue8 As Byte 存蓝色的值Dim Pos8 As LongDim endYanse8 As BytePos8 = 11For IY = Gao8 - 1 To 0 Step -1 y行 。描点For IX = 0 To Kuan8 - 1 x列 Get #3, Pos8, endYanse8 得到颜色 yanseRed8 = Fix(endYanse8 / 6 / 6) yanseGreen8 = Fix(endYanse8) / 6) Mod 6 yanseBlue8 = endYanse8 Mod 6 Picture3.PSet (IX, IY), RGB(yanseRed8 * 42, yanseGreen8 * 42, yanseBlue8 * 42) Pos8 = Pos8 + 1Next IX Pos