怎样将jpg图片转化成bmp图片

Question

我在向access数据库中存图片时发现只能存bmp格式的
请给出代码谢谢

Answer 1

function Bmp2JPG(BmpFileName,JPGFileName:string;CompressRate:integer=86):boolean;
將BMP圖檔轉為JPG圖檔,BMP檔名為BmpFileName,JPG檔名為JPGFileName,CompressRate為JPG圖檔的壓縮率,若不傳入此參數內定為86%壓縮率.function JPG2BMP(JPGFileName,BmpFileName:string):boolean;
將JPG圖檔轉為BMP圖檔,JPG檔名為JPGFileName,BMP檔名為BmpFileNamefunction Bmp2JPG(BmpFileName,JPGFileName:string;CompressRate:integer=86):boolean;
var jpg:TJPEGImage;
    bmp:tBitMap;
begin
  jpg:=TJPEGImage.create;
  bmp:=TBitMap.create;
  result:=true;
  try
    bmp.LoadFromFile(BmpFileName);
    jpg.assign(bmp);
    jpg.CompressionQuality:=CompressRate;
    jpg.SaveToFile(JPGFileName);
  except
    result:=false;
  end;
  jpg.free;
  bmp.free;
end;
function JPG2BMP(JPGFileName,BmpFileName:string):boolean;
var jpg:TJPEGImage;
    bmp:tBitMap;
begin
  jpg:=TJPEGImage.create;
  bmp:=TBitMap.create;
  result:=true;
  try
    jpg.loadfromfile(JPGFileName);
    bmp.assign(jpg);
    bmp.SaveToFile(BmpFileName);
  except
    result:=false;
  end;
  jpg.free;
  bmp.free;
end;

Answer 2

>>我在向access数据库中存图片时发现只能存bmp格式的应该是你操作有误，可以存jpg的

Answer 3

http://www.delphibbs.com/keylife/iblog_show.asp?xid=8023

Answer 4

这是我向数据库中直接存jpg文件的代码，运行时报无效位图长度错误。各位看一下问题何在。if extractfileext(s)='.jpg' then begin
      showmessage('j');
      M_Jpeg.LoadFromFile(s);
    
     
      M_Jpeg.SaveToStream(MS_JpegStream);
  
      image2.Picture.Assign(M_Jpeg);
      showmessage('ting');
      table1.Edit;
      TBlobField(table1.FieldByName('graph')).LoadFromStream(MS_JpegStream);
      table1.Post;
end;

Answer 5

procedure TForm1.BitBtn1Click(Sender: TObject);
var
  Jpeg:TJpegImage;
  bmp:TBitmap;
begin
   bmp:=TBitmap.Create;
   jpeg:=TJpegImage.Create;   jpeg.LoadFromFile('c:\aa.jpg');
    
   bmp.Assign(jpeg);   ADOQuery1.Insert;
   TBlobField(ADOQuery1.FieldByName('Image')).Assign(bmp);
   ADOQuery1.Post;   bmp.Free;
   jpeg.Free;
end;

Answer 6

问题是转化无错但是当进行数据库操作时，系统提示 invalid bitmap！！！！

Answer 7

转化很简单的，用image来load一个jpg，image再save，就是bmp的了