Cannot put text in image in spreadsheet while creating PDF using XMLWorker

Question

I have an html file and it allows XMLWorkerHelper to parse it so that it can generate PDF.

In html. In a table cell, I can put text in an image. but when i do

worker.parseXHtml (pdfWriter, document, isr);
it does not put text in the image,

isr is ByteArrayInputStream mockHttpServletResponse.

In html, I used the whole styling style. But that does not work.

Please let me know how I can do this.