Delphi to achieve suspended karaoke subtitles

GDI + realizes transparent watermark and text recently added watermark function to "JPEG browse scaler", in the process of design, reference the article on the net, but found that the GDI + API package used by the article is not the one that I use now, the GDI + API package currently used by Delphi has two sets, The set includes directdraw.*, gdipapi.*, gdipobj.*, gdiputil.* as filenames, and another set of gdipexport.*, gdiplus.*, gdiptypes.*, gdiputil.* as filenames, I use the former, the article is the latter, so the article original code according to the set of GDI + API package I used to modify, the modified code is as follows:

USES Gdiputil,gdipapi,gdipobj;

Procedure form1.savejpg (sname,dname:string);

sname-source JPEG file name, dname-JPEG file name after watermark

Const

Colormatrix:tcolormatrix =
( //r G B A V
(1.0, 0.0, 0.0, 0.0, 0.0),
(0.0, 1.0, 0.0, 0.0, 0.0),
(0.0, 0.0, 1.0, 0.0, 0.0),
(0.0, 0.0, 0.0, 0.3, 0.0),
(0.0, 0.0, 0.0, 0.0, 1.0)
);
Var
Font1:tgpfont;
Bmp,watermark:tgpbitmap;
G:tgpgraphics;
Sb1:tgpsolidbrush;
Imageattr:tgpimageattributes;
Jpg:tgpimage;
Strformat:tgpstringformat;
Encoderclsid:tguid;
Parameters:tencoderparameters;
Quality:integer;

Begin

//Loading JPEG images
Jpg:=tgpimage.create (sname);
//Create a BMP based on the size of the JPEG image
BMP: = tgpbitmap.create (jpg). Getwidth,jpg. GetHeight, Pixelformat32bpprgb);

Draw a JPEG Basemap
G: = Tgpgraphics.create (BMP);
G.setinterpolationmode (interpolationmodehighqualitybicubic);
G.drawimage (JPG, makerect (0, 0, Jpg.getwidth,,jpg.getheight), 0, 0, jpg.getwidth, Jpg.getheight, Unitpixel);

Use BMP format image in image control to make watermark map
Watermark:=tgpbitmap.create (Image1.Picture.Bitmap.Handle, PIXELFORMAT32BPPRGB);
 

Set the watermark's opacity to 0.3 (according to ColorMatrix's [3][3]=0.3)
Imageattr: = tgpimageattributes.create;
Imageattr.setcolormatrix (ColorMatrix:);

//Draw watermark, position in the upper left corner of the original x=20,y=20 bit, force the size to 100*100.
G.drawimage (Watermark, Makerec (20,20, 100,100), 0, 0
Image1.picture.bitmap.width,image1.picture.bitmap.height, Unitpixel, imageattr);

Add watermark Text

Font1: = Tgpfont.create (' blackbody ', 20);

SB1: = Tgpsolidbrush.create ($50000000); Black Shadow Bottom
SB2: = Tgpsolidbrush.create ($50FFFFFF); White word on top

Strformat: = tgpstringformat.create;
Strformat.setalignment (stringalignmentnear);

Use black and white to stagger 1 pixels to draw text, creating a shadow effect.

g.DrawString (' Chong Pupil software Studio ', 7,font1,makerect (151,21,jpg.getwidth/1,jpg.getheight), STRFORMAT,SB1);
g.DrawString (' Chong Pupil software Studio ', 7,font1,makerect (150,20,jpg.getwidth/1,jpg.getheight), STRFORMAT,SB1);

------Set the image quality encoding parameters, save the file---------------------
Quality: = 90;
Parameters.count: = 1;
Parameters.parameter[0]. Guid: = encoderquality;
Parameters.parameter[0]. Type_:= Encoderparametervaluetypelong;
Parameters.parameter[0]. NumberOfValues: = 1;
//Set parameter values: Quality level, up to 100, image file size proportional to quality
Parameters.parameter[0]. Value: = @Quality;
Getencoderclsid (' Image/jpeg ', encoderclsid);
Bmp.save (Dname, Encoderclsid, @Parameters);

Release
SB1. Free;
Font1. Free;
Strformat.free;
Jpg. Free;
Bmp. Free;
Imageattr.free;
Watermark.free;
G.free;

End

In the online article, Tgpsolidbrush.create ($50000000); This function with the parameter is $99000000, draw the text is opaque, and in the web also did not search to draw transparent text code, once made me think to make text transparent, must first save as a picture, and then use the method of drawing watermark to realize, later thought, is not arbg a (transparency) too big, In GDI +, use arbg,$99000000 to represent a=$99, try to change the color of a to $, text transparency effect is out.

Http://www.cnblogs.com/hssbsw/archive/2012/06/03/2533088.html

Delphi to achieve suspended karaoke subtitles