Thank you for your question and photo. Due to limited resolution of the photo, it is difficult to conclusively diagnose the type of pigmentation that you have. It looks like you have solar lentigines and/or melasma. It would be best if you consult a doctor for a definitive diagnosis.
Depending on the type of pigmentation you have, a combination of laser (e.g. Q switch laser) and topical whitening agents e.g. Hydroquinone, Azelaic acid, Kojic acid etc. may be used. Type and number of sessions needed again depends on the type of pigmentation you have. Response to treatment varies between individuals but in general, 5-10 sessions of laser are needed.
To prevent worsening of your pigmentation, application of adequate sunblock (re-apply every 2-3 hours if possible) and avoidance of excessive sun exposure is key.
Hope this would be useful to you.
Best regards,
Dr. Soh