A very quick entry this time. The previous week I had to email some documents manually signed. You know, print, sign, scan and send. The problem was some documents have a lot of pages and I only had to sign the last one. So I decided to, instead of print and scan all the pages, just do it for the last one, the one that I need to modify signing it, and re-arrange the pdf again.
In summary, I developed a simple java tool to transform a pdf into images (each page is an image) and a set of images into a pdf (each image is a page). It is a very simple tool because pdfbox can handle all pdf work and ImageIO all image stuff. The tool is a converter to do the transformation both ways. This way I could convert original pdf to images, substitute the last the last one with the signed one and transform back the images to a final pdf.