asked on

Thumbnails?

My program works with own custom documents and sometimes user creates templates from them.
also there is a background picture into documents. I want to make 'new from template' dialog form that shows thumbnails of my document;s background. SO my question is :
-how to create thumbnail from my background pictures (jpegs)?

thanks in advance.

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Cesario Lababidi

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Mohammed Nasman

Hello

Here's procedure called MakeThumb, just pass the two images as source and target and the thumbnail size

//=====
procedure MakeThumb(src,dst:TImage; size:integer);
var tr:TRect;
newwidth,newheight,orgwidth,orgheight:integer;
begin
orgwidth:=src.width;
orgheight:=src.height;
if (orgheight/orgwidth > 1) then begin
newheight:=size;
newwidth:=round(orgwidth*(newheight/orgheight));
end
else begin
newwidth:=size;
newheight:=round(orgheight*(newwidth/orgwidth));
end;
dst.autosize:=false;
dst.stretch:=false;
dst.width:=size;
dst.height:=size;
dst.canvas.pen.color:=clwhite;
dst.canvas.brush.color:=clwhite;
if (newwidth < size)then begin
tr.left:=(size-newwidth)div 2;
tr.right:=tr.left+newwidth;
tr.top:=0;tr.bottom:=size;
dst.canvas.rectangle(0,0,tr.left,size); // fill white
dst.canvas.rectangle(tr.right,0,size,size);// fill white
end;
if newheight > size then begin
tr.left:=0;tr.right:=size;
tr.top:=(size-newheight)div 2;
tr.bottom:=tr.top+newheight;
dst.canvas.rectangle(0,0,size,tr.top); // fill white
dst.canvas.rectangle(0,tr.bottom,size,size);// fill white
end;
dst.canvas.stretchdraw(tr,src.picture.graphic);
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
makethumb(image1,Image2,100);
end;

Best regards
Mohammed nasman