Mega Code Archive
Change the size of an JPEG image and save it
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Title: Change the size of an JPEG image and save it
Question: How to change the size (width and heigth) of an JPEG file and save it with the changed size?
Answer:
[(time: Few hours later) Update: Now the image will not be stretched out, the width and height scale stays the same :)]
- Add the JPEG unit to your uses
- Add a OpenDialog and SaveDialog to your form
Use this code to chnage the size of a JPEG image:
var
jpegImage: TJPegImage;
bitmap: TBitmap;
begin
jpegImage := TJPegImage.create;
OpenDialog1.Execute;
jpegImage.loadFromFile( OpenDialog1.FileName );
// We create a bitmap with the right dimensions
bitmap := TBitmap.create;
bitmap.width := 200;
bitmap.height := round(jpegImage.Height/(jpegImage.Width/200));
// We draw the jpeg image onto the bitmap
bitmap.canvas.stretchDraw( rect( 0,0, 200,
round(jpegImage.Height/(jpegImage.Width/200)) ), jpegImage );
// We copy the bitmap back to the jpeg and save
jpegImage.Assign( bitmap );
jpegImage.jpegNeeded;
jpegImage.saveToFile('c:\picture.jpg');
end;
You can make this procedure bigger and bigger ofcourse, but this is the basic.
(ps. Don't be to hard on me, this is my very first article of this year. Thanks :) )
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