I tried to add a PNG file (transparent background) on a PDF by using “PDF Stamp” but I only got a black square.
I would like to know is “PDF Stamp” support stamp a transparent PNG on PDF?
If it is support, what format of image is prefer?
Yes, our PDFStamp Command Line and PDFStamp SDK products are support transparent PNG image,
For example, you can use following command line to stamp your PDF file with attached transparent PNG image properly,
This is the stamped PDF file, as you see, the stamp is the transparent PNG image, it has opacity option too,
pdfstamp.exe -PDF pdftest.pdf -O "_testout.pdf" -AI "testseal.png" -MLR100 -MTB100 -W50 -H50 -opacity50
please refer to original PDF file and stamped PDF file in attachment.
How about PDFStamp COM?
PDFStamp COM and PDFStamp SDK are same product, so PDFStamp COM has transparent function too, for example,
#define Very_Set_Opacity 240
#define Very_Set_TransparentColor 242
//Show image with "opacity" feature,
VeryStampSetFunction(id, Very_Set_Opacity, 30, 0, 0, 0);
VeryStampAddImage( id, 7, "logo.jpg",30,-30,0,0,0,0,0,0,0);
VeryStampAddImage( id, 3, "logo.jpg",-30,30,0,0,0,0,0,0,0);
//Show image with "transparence" feature,
//Convert white color to transparent background
VeryStampSetFunction(id, Very_Set_TransparentColor, 1, RGB(255,255,255), 0, 0);
VeryStampAddImage( id, 1, "logo.jpg",0,0,0,0,0,0,0,0,0);
I only can find VertSetFunction() in my documentation and download evaluation SDK.
Are they the same?
Yes, VeryStampSetFunction() and VertSetFunction() are same, you can use VertSetFunction() to instead of VeryStampSetFunction() function.
If you can't get your code to work, please email your test project to us, we will debug your test project and come back to you asap.