I was wondering if I can remove a watermark from an image created by me. I used a software to create the image (namely, Visual Paradigm Online): if I subscribe to a commercial license, the software doesn't apply a watermark. Instead, if I subscribe to the free license, I am still the author of the image (and I have all the rights on the image), but the software applies a watermark to the image.
This is the image, showing two watermarks in the upper left corner and in the lower right corner. The watermarks consist of the line of text "Visual Paradigm Online Express Edition":
I am the author of the image, so I am trying to remove a watermark from a work made by me. The reason why the image has a watermark is that the software I used to make the image wants to incentivize the purchase of a commercial license. I am the author of the image, so I am free to use the watermarked image in my works and I own all the rights on the watermarked image. I think that, since I am the author of the image, I have the right to remove the watermark from the image. I don't think that the software can claim to be "co-author" and, thus, claim rights on the image. Am I right?