如何将Timage下保存为压缩过的jpg文件？(100分)

X

xiecc

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• 1999-11-08

• #1

我直接用Image1.Picture.SaveToFile('X.jpg');结果保存后的Jpg文件大小
与bmp文件的大小一样，后来我想用
TJpegImage(Image1.Picture.Graphic).Compress;
Image1.Picture.SaveToFile('X.jpg');
结果出错，请教有何办法？

 

K

kzl

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• 1999-11-08

• #2

将TImage中的图形传递给TJpegImage，
再调用TJpegImage的Compress和SaveToFile

 

A

amo

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• 1999-11-08

• #3

呵呵，
你这么保存就是保存成bmp文件，不过后缀是jpg吧了。

 

A

amo

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• 1999-11-08

• #4

这样是不能转换的，
看看帮助：
TJPEGImage has an internal bitmap that represents the JPEG image.
This internal image and the original source of the JPEG image are
~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~
read only.
~~~~~~~~~~

 

C

CJ

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• 1999-11-08

• #5

hehe, try use canvas.copyrect, then save

 

C

cAkk

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• 1999-11-09

• #6

var jpg:tjpeimage;
bmp:tbitmap;
begin
jpg:=tjpegimage.create;
jpg.assign(bmp);
jpg.picture.savetofile('x.jpg');

BTW: jpg格式默认好像就是压缩的吧? 不用显式调用compress

 

C

cytown

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• 1999-11-09

• #7

var
jpeg1:tjpegimage;
begin
jpeg1:=tjpegimage.create;
jpeg1.assign(image1.picture.graphic);
jpeg1.compress;
jpeg1.savetofile('test.jpg');
jpeg1.free;
end;

 

L

Liu JZX

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• 1999-11-09

• #8

uses jpeg;

procedure TForm1.Button1Click(Sender: TObject);
var
jpeg1:TJpegImage;
begin
Jpeg1 := TJpegImage.Create;
Jpeg1.CompressionQuality := 50;
Jpeg1.Assign(Image1.Picture.Bitmap);
jpeg1.SaveToFile('c:/mydocu~1/liu.jpg');
end;

 

M

menxin

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• 1999-12-14

• #9

请继续讨论或结束问题

 

L

liuminghao

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• 2000-03-03

• #10

总的来说，用Tjegimage.assign把一个Tbitmap装入，再保存或输出就可以得到一个
*.jpeg图片文件，如果调用CompressionQuality属性你还可以调整压缩率（一般75
较合适）。
procedure TForm1.Button1Click(Sender: TObject);
var
jp1:TJpegImage;
begin
jp1 := TJpegImage.Create;
jp1.Assign(Image1.Picture.Bitmap);
jp1.SaveToFile('c:/x.jpg');
jp1.free;
end;

 

J

JohnsonGuo

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• 2000-03-25

• #11

procedure ...
begin
with TJpegImage.Create do
try
CompressionQuality:=65;
Assgin(Image1.Picture.Graphic);
SaveToFile('c:/demo.jpg');
finally
Free;
end;
end;

 

X

xiecc

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• 2000-03-27

• #12

多人接受答案了。