resize image

additional to stretch set the proportional-property to true

meikl ;-)

download an example from:   http://www.geocities.com/esoftbg
                                  link:   D7 code Q_20893588.zip

emil

hi meikl,
the code is below:

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ExtCtrls, StdCtrls, Buttons;

type
  TForm1 = class(TForm)
    Image1: TImage;
    BitBtn1: TBitBtn;
    BitBtn2: TBitBtn;
    BitBtn3: TBitBtn;
    BitBtn05: TBitBtn;
    procedure FormCreate(Sender: TObject);
    procedure BitBtn1Click(Sender: TObject);
    procedure BitBtn2Click(Sender: TObject);
    procedure BitBtn3Click(Sender: TObject);
    procedure BitBtn05Click(Sender: TObject);
  private  { Private declarations }
  public   { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure GetTrueSize(Image: TImage; var H: Integer; var W: Integer);
begin
  try
    H := Image.Picture.Bitmap.Height;
    W := Image.Picture.Bitmap.Height;
  except
    H := 0;
    W := 0;
  end;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  Image1.Picture.LoadFromFile('153_139_ATHENA.BMP');
end;

procedure TForm1.BitBtn1Click(Sender: TObject);
var
  H:      Integer;
  W:      Integer;
begin
  GetTrueSize(Image1, H, W);
  Image1.Stretch := False;
  Image1.Height := H;
  Image1.Width := W;
end;

procedure TForm1.BitBtn2Click(Sender: TObject);
var
  H:      Integer;
  W:      Integer;
begin
  GetTrueSize(Image1, H, W);
  Image1.Stretch := True;
  Image1.Height := H*2;
  Image1.Width := W*2;
end;

procedure TForm1.BitBtn3Click(Sender: TObject);
var
  H:      Integer;
  W:      Integer;
begin
  GetTrueSize(Image1, H, W);
  Image1.Stretch := True;
  Image1.Height := H*3;
  Image1.Width := W*3;
end;

procedure TForm1.BitBtn05Click(Sender: TObject);
var
  H:      Integer;
  W:      Integer;
begin
  GetTrueSize(Image1, H, W);
  Image1.Stretch := True;
  Image1.Height := Round(H/2);
  Image1.Width := Round(W/2);
end;

end.

Hi,

Meikl, i am using delphi5 , i dont find a proportional property.

i think emils solution will work.

my problem is i get images in different sizes.

i have to display then in an area(lengthxwidth) of 120 X 120.

if the image is smaller then 120x120 i dont have to do anything,simply display them.

however if they are bigger then that (eg 200X50 or 300X200) , then i have to proportionately rezise them to fit into the 120x120 area without any distortion

emil can you please modify your code to achive this.

Hi earlrainer, try next:

procedure GetTrueSize(Image: TImage; var H: Integer; var W: Integer);
begin
  try
    H := Image.Picture.Bitmap.Height;
    W := Image.Picture.Bitmap.Width;
  except
    H := 0;
    W := 0;
  end;
end;

procedure TForm1.BitBtn120Click(Sender: TObject);
const
  DSize:  Double = 120;
var
  H:      Integer;
  W:      Integer;
  D:      Double;
begin
  GetTrueSize(Image1, H, W);
  if ((H>DSize) or (W>DSize)) then
  begin
    Image1.Stretch := True;
    if (H=W) then
      D := DSize/H
    else
    if (H>W) then
      D := DSize/(H)
    else
      D := DSize/(W);
    Image1.Height := Round(D*H);
    Image1.Width := Round(D*W);
  end;
end;

emil

ooops:
 
    if (H>=W) then
      D := DSize/H
    else
      D := DSize/W;

procedure ResizeImage(Image: TImage; DSize:  Double);
var
  H:      Integer;
  W:      Integer;
  D:      Double;
begin
  D := 0;
  H := 0;
  W := 0;
  try
    H := Image.Picture.Bitmap.Height;
    W := Image.Picture.Bitmap.Width;
    if ((H>DSize) or (W>DSize)) then
    begin
      Image.Stretch := True;
      if (H>W) then
        D := DSize/H
      else
        D := DSize/W;
    end;
  finally
    Image.Height := Round(D*H);
    Image.Width := Round(D*W);
  end;
end;

procedure TForm1.BitBtn120Click(Sender: TObject);
const
  DSize:  Double = 120;
begin
  ResizeImage(Image1, DSize);
end;

thanks

Hi Emil,

As an extension to your above code snippet, could you make it so that after your resize, the image is centred?

I tried:

procedure ResizeImage(Image: TImage; DSize:  Double);
var
  H:      Integer;
  W:      Integer;
  D:      Double;
begin
  D := 1;
  H := Image.Picture.Bitmap.Height;
  W := Image.Picture.Bitmap.Width;
  try
    Image.Center := False;
    if ((H>DSize) or (W>DSize)) then
    begin
      Image.Stretch := True;
      if (H>W) then
        D := DSize/H
      else
        D := DSize/W;
    end;
  finally
    Image.Stretch := False;
    Image.Center := True;
    Image.Height := Round(D*H);
    Image.Width := Round(D*W);
  end;
end;

but to no avail... a quick 250 pts for a working answer.



DragonSlayer

DragonSlayer,
the question is about to keep proportion of the image and set its stretch property to true:

>i want to make smaller images from the bigger images i Have.
>i can use Timage and set its stretch property to true.
>but i lose the proportion of height:width of the image.
>is it possible to make smaller images but still retaining the proportion

you have an iteresting solution, but it is out of requirement: Image.Stretch := True;
and using it we see the central zone of the image. The proportion is kept.
After all this question is for 50 points  ;-)

emil

erm... emil... you got me wrong :-)

What i said was, I am offering 250pts for you, to still retain the above code but to make it center as well. Meaning, I still need proportionate resize, but I want the output of the resize to be centred in the TImage.. e.g. if after a resize of a 140x150 JPEG on a 300x300 TImage, the image will appear to the left, with 20 pixels left in the TImage.

Now is there a way for me to center it so that I have 10 pixels on both sides of the TImage as compared to having 20 pixels on the right?

The Image.Center := True code was what I tried, but it didn't work... I still have 20 pixels to the right.


DragonSlayer.

you might take a look to

https://www.experts-exchange.com/questions/10185579/Scroll-drag-a-TImage.html

meikl ;-)

Hi meikl, that's what I'm currently doing too... "cheating" a bit by repositioning the TImage instead. But I was wondering if Emil (or anyone else) can post code to Center it inside the TImage instead of centering the TImage in a Parent Control

>can post code to Center it inside the
>TImage instead of centering the TImage in a Parent Control

in this case you have to create a bitmap with size og the timage-control,
and paint there ceneterd your minimized picture

meikl ;-)

erm... no intermediate TBitmaps... can anything be done on a single TImage? And the sizes of my bitmaps can be of any width x height