Draw logos in your images with GdiPlusX

Another common request that I always find on some VFP forums is people wanting to draw some images, usually company logos over some pictures. this is really simple, as i'll show below.

For all the samples that i'll provide the vfpx logo will be drawn in some bigger pictures. to show all the flexibility that gdi+ can offer to us, some effects will be aplied to the logo.

ImportantRequires VFP9 and the Gdiplusx library to run.  

Please make sure that you have the latest version!
https://github.com/VFPX/GDIPlusX

sample 1: draw image without transformation



do locfile("system.app")

with _screen.system.drawing as xfcdrawing

local lcmainpict, lclogopictlocal lomainbmp as xfcbitmaplocal lologobmp as xfcbitmaplocal logfx as xfcgraphics

lcmainpict = getpict()
lclogopict = getpict()

lomainbmp = .bitmap.fromfile(lcmainpict)
lologobmp = .bitmap.fromfile(lclogopict)
logfx = .graphics.fromimage(lomainbmp)

*!* example 1
*!* original image
*!* position : top left
*!* draw logo without any transformationlogfx.drawimage(lologobmp, 0, 0)
lomainbmp.save("c:\logo1.jpg", .imaging.imageformat.jpeg)

* show imagerun /n explorer.exe c:\logo1.jpgendwith



sample 2 : convert the white background of our logo to transparent, using the bitmap.maketransparent() function



do locfile("system.app")

with _screen.system.drawing as xfcdrawing

local lcmainpict, lclogopictlocal lomainbmp as xfcbitmaplocal lologobmp as xfcbitmaplocal logfx as xfcgraphics

lcmainpict = getpict()
lclogopict = getpict()

lomainbmp = .bitmap.fromfile(lcmainpict)
lologobmp = .bitmap.fromfile(lclogopict)
logfx = .graphics.fromimage(lomainbmp) *!* sample 2
*!* converted selected color from logo with alpha 255 (opaque) to transparent alpha (0)
*!* position : top right
* force the white background from the logo to become transparentlologobmp.maketransparent(.color.white)

* draw logo at the top right position of imagelocal x1, y1
x1 = lomainbmp.width - lologobmp.widthy1 = 0
logfx.drawimage(lologobmp, x1, y1)
lomainbmp.save("c:\logo2.jpg", .imaging.imageformat.jpeg)

run /n explorer.exe c:\logo2.jpgendwith



sample 3 : draw the logo aplying 25% transparency to the whole image.

the transparency is aplied to the whole image using a colormatrix. the transparency ratio that is aplied ranges from 0 (totally transparent) to 1 (totally opaque).


 
do locfile("system.app")

with _screen.system.drawing as xfcdrawing

local lcmainpict, lclogopictlocal lomainbmp as xfcbitmaplocal lologobmp as xfcbitmaplocal logfx as xfcgraphics

lcmainpict = getpict()
lclogopict = getpict()

lomainbmp = .bitmap.fromfile(lcmainpict)
lologobmp = .bitmap.fromfile(lclogopict)
logfx = .graphics.fromimage(lomainbmp)

*!* sample 3
*!* draw the logo aplying 25% transparency to the whole image
*!* position: bottom left
* the transparency is aplied to the whole image
* define the transparency ratio that will be aplied
* this parameter ranges from 0 (totally transparent) to 1 (totally opaque)local lntranspratio
lntranspratio = 0.25 && 25%

* create a colormatrix that will have the transformations information
* the position (4,4) of the matrix is responsible for the opacity local loclrmatrix as xfccolormatrix
loclrmatrix = .imaging.colormatrix.new( ;
   1, 0, 0, 0 , 0, ;
   0, 1, 0, 0 , 0, ;
   0, 0, 1, 0 , 0, ;
   0, 0, 0, lntranspratio, 0, ;
   0, 0, 0, 0 , 0)

* create an image attributes object to create the effects based in our clrmatrixlocal loattr as xfcimageattributes
loattr = .imaging.imageattributes.new()
loattr.setcolormatrix(loclrmatrix)

* we need to create a rectangle that will contain the coordinates and size of the transformed logolocal lorect as xfcrectangle
lorect = .rectangle.new()
lorect.x = 0
lorect.y = lomainbmp.height - lologobmp.heightlorect.width = lologobmp.widthlorect.height = lologobmp.height * draw the transformed image using the rectangle and imgattributes/clrmatrixlogfx.drawimage(lologobmp, lorect, lologobmp.getbounds(), .graphicsunit.pixel, loattr)
lomainbmp.save("c:\logo3.jpg", .imaging.imageformat.jpeg)

run /n explorer.exe c:\logo3.jpgendwith 


sample 4 : draw the logo with transparent background with 50% global transparency.
aply 100% transparency to the white color, to eliminate the background
draw the logo aplying 50% transparency to the whole image, similar to the previous sample.

 


do locfile("system.app")

with _screen.system.drawing as xfcdrawing

local lcmainpict, lclogopictlocal lomainbmp as xfcbitmaplocal lologobmp as xfcbitmaplocal logfx as xfcgraphics

lcmainpict = getpict()
lclogopict = getpict()
lomainbmp = .bitmap.fromfile(lcmainpict)
lologobmp = .bitmap.fromfile(lclogopict)
logfx = .graphics.fromimage(lomainbmp)
 *!* sample 4
*!* aply 100% transparency to the white color, to eliminate the background
*!* draw the logo aplying 50% transparency to the whole image
*!* position: top left
* first step: eliminate the white backgroundlologobmp.maketransparent(.color.white)

* define the transparency ratio that will be aplied
* this parameter ranges from 0 (totally transparent) to 1 (totally opaque)local lntranspratio
lntranspratio = 0.50 && 50%

* create a colormatrix that will have the transformations information
* the position (4,4) of the matrix is responsible for the opacity local loclrmatrix as xfccolormatrix
loclrmatrix = .imaging.colormatrix.new( ;
   1, 0, 0, 0 , 0, ;
   0, 1, 0, 0 , 0, ;
   0, 0, 1, 0 , 0, ;
   0, 0, 0, lntranspratio, 0, ;
   0, 0, 0, 0 , 0)

* create an image attributes object to create the effects based in our clrmatrixlocal loattr as xfcimageattributes
loattr = .imaging.imageattributes.new()
loattr.setcolormatrix(loclrmatrix)

* we need to create a rectangle that will contain the coordinates and size of the transformed logolocal lorect as xfcrectangle
lorect = .rectangle.new()
lorect.x = 0
lorect.y = 0
lorect.width = lologobmp.widthlorect.height = lologobmp.height * draw the transformed image using the rectangle and imgattributes/clrmatrixlogfx.drawimage(lologobmp, lorect, lologobmp.getbounds(), .graphicsunit.pixel, loattr)
lomainbmp.save("c:\logo4.jpg", .imaging.imageformat.jpeg)

run /n explorer.exe c:\logo4.jpgendwith