Optimise-a-dbimage-fields-and-free-space-on-the-disk


            Title: optimise a dbimage fields and free space on the disk
Question: how to reduce the size of dbimage and optimise the dbimage fields
or graphic field.
Answer:
we know that after scanning a photo and save it in a dataset the place assigned 
on the disk depend of the size of the image and on the parametres of scanning way, so if we have to scan n photos we have to optimise and reduce the size of photos stored in the dataset.
this a unit of my project
{ this project is for optimise the blob fields as photos
 after execute this project you will pack the table}
//***************************************************
// before you have to create a form
// dbnavigator1
// dbimage1 with the specified field to optimise
// image1
// datamodule2 unit
// gauge1
// SpeedButton1
//***************************************************
unit optimise;
interface
uses
 Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
 ExtCtrls, StdCtrls, Buttons, Mask,ComCtrls,DBCtrls,jpeg, Gauges;
type
 TFoptimise = class(TForm)
 SpeedButton1: TSpeedButton;
 Gauge1: TGauge;
 Image2: TImage;
 DBImage1: TDBImage;
 DBNavigator1: TDBNavigator;
 procedure FormShow(Sender: TObject);
 procedure SpeedButton1Click(Sender: TObject);
 procedure FormClose(Sender: TObject; var Action: TCloseAction);
 private
 { Private declarations }
 public
 { Public declarations }
 end;
var
 Foptimise: TFoptimise;
implementation
uses Unit2;
//unit2 is datamodule2 unit
{$R *.DFM}
function resizeImage(sInImage, sOutImage: string; iHeight, iWidth: integer): boolean;
 var
 JpgImg : TJpegImage;
 BmpImg : TBitmap;
 Rectangle: TRect;
 begin
 try
 			JpgImg := TJpegImage.Create;
 	BmpImg := TBitmap.Create;
 	JpgImg.LoadFromFile(sInImage);
 	Rectangle := Rect(0, 0, iWidth, iHeight);
 	with BmpImg do
 	begin
 	Width := iWidth;
 	Height := iHeight;
 	Canvas.StretchDraw(Rectangle, JpgImg);
 	end;
 		finally
 	JpgImg.Assign(BmpImg);
 	 JpgImg.SaveToFile(sOutImage);
 	JpgImg.Free;
 	BmpImg.Free;
 		end;
 Result := True;
 end;
Function ConvertJpegToBmp(imgJpeg : TJPEGImage; Var imgBmp : TBitMap) : Boolean;
// Converti une image Jpeg en BMP
begin
 Result:=True;
 try
 ImgBMP.Width := ImgJPEG.Width; // dtermination de la taille de ImgBmp
 ImgBMP.Height := ImgJPEG.Height;
 ImgBMP.Canvas.Draw(0,0,ImgJPEG); // On dessine de ImgJPEG dans ImgBmp
 Except
 On E:Exception do Result:=False;
 end;
end;
Function FileConvertJpegToBmp(JpegFile,BmpFile : String) : Boolean;
// Converti un fichier Jpeg en fichier BMP
var
 ImgJPEG : TJPEGImage;
 ImgBmp : TBitmap;
begin
 Result:=False;
 try
 try
 ImgJPEG := TJPEGImage.Create;
 ImgBmp := TBitmap.Create;
 ImgJPEG.LoadFromFile(JpegFile); // chargement du JPEG partir d'un fichier
 if ConvertJpegToBmp(ImgJPEG,ImgBmp) then
 begin
 ImgBmp.SaveToFile(BmpFile); // Sauvegarde de ImgBmp sous fichier
 Result:=True;
 end;
 Except
 On E:Exception do ;
 end;
 finally
 ImgJPEG.Free;
 ImgBmp.Free;
 end;
end;
procedure TFoptimise.FormShow(Sender: TObject);
begin
 datamodule2.Table1.open;
end;
procedure TFoptimise.SpeedButton1Click(Sender: TObject);
var
 Imgbmp:TBitMap;
 jpgImg2: TJPEGImage;
 MyFormat:word;
 Bitmap : TBitMap;
 AData,APalette : THandle;
 photo1,photo2,photo3,photo4:string;
begin
image2.Visible:=True;
gauge1.Visible:=True;
gauge1.MaxValue:=DataModule2.table1.RecordCount;
gauge1.Progress:=0;
DataModule2.table1.First;
photo1:=datamodule2.Session1.NetFileDir+'\constphoto.bmp';
photo2:=datamodule2.Session1.NetFileDir+'\constphoto.jpg';
photo3:=datamodule2.Session1.NetFileDir+'\constphoto3.jpg';
photo4:=datamodule2.Session1.NetFileDir+'\constphoto5.jpg';
while not (datamodule2.Table1.eof) do
 begin
 gauge1.Progress:=gauge1.Progress+1;
if not((Datamodule2.Table1photo.BlobSize=0) or (Datamodule2.Table1photo.isnull)) then
begin
 dbimage1.Picture.SaveToFile(photo1);
 image2.picture.LoadFromFile(photo1);
 Image2.Refresh;
 //conversion BMP -JPG
 jpgImg2 := TJPEGImage.Create;
 jpgImg2.Assign(Image2.Picture.Bitmap);
 jpgImg2.SaveToFile(photo2);
 //RESIZE
 resizeImage(photo2,photo3,128,128);
 image2.picture.LoadFromFile(photo3);
 datamodule2.Table1.edit;
 FileConvertJpegToBmp(photo3,photo4);
 dbimage1.picture.Bitmap.LoadFromFile(photo4);
 datamodule2.Table1.post;
 deletefile(photo4);
end;
Datamodule2.table1.next;
end;
gauge1.Visible:=false;
image2.Visible:=False;
end;
procedure TFoptimise.FormClose(Sender: TObject; var Action: TCloseAction);
begin
datamodule2.Table1.close;
end;
end.
// after try to pack the dataset table.
Graphic Delphi
