Enhance line quality

I have the image in pic (black and white image) and I would like to increase the quality of the lines, which appear blurred. I tried to use the erode filter in gimp. The quality has improved a bit but not enough. Is there a way to improve the lines of a simple image like this and vectorize it using gimp or inkscape?

How to colorize an translucent picture in Photoshop?

I’ve got a scanned picture of a sticker album which contains an translucent room where the sticker should be sticked. I’ve tried (using the Equalize, Curves, Levels, Vibrance and Contrast Tools from Photoshop) to get the translucent room as close as possible to the real sticker, but I feel that I still can do something to improve it. Could someone give me, kindly, some hint about this situation?