Grainy photographs can be the result of a number of issues, such as a low-quality camera or a dark background when taking the picture. Adobe Photoshop is a computer software program that can help repair such photos, as Photoshop specializes in photo editing. That's not to say that getting a grainy photo to look sharp is simple. Sometimes you need to try several different methods via Photoshop before getting the look you want.
Open your photograph in Photoshop. Click on "File," and then "Save As," then rename the file when prompted. This will allow you to save the original photo because, again, you may want to make a variety of edits on the same picture.
Select the "Filter" option, then drag down to "Noise." After you click on "Noise," you will be given an option to "Reduce Noise." Drag you cursor over the "Reduce Noise" option and release.
Adjust the sliders in the pop-up window that appears after you click "Reduce Noise." There will be a window showing you what changes are being made as you move the sliders, so you can tell how the picture will look as you make the necessary adjustments. Once you have adjusted the sliders and improved the sharpness of the picture, click "OK" in the pop-up window.
Grab the smudge tool from the Photoshop toolbox, in the event your photo is still not as sharp as you would like -- or if there are still grainy portions. Zoom in to work on a specific portion of the photo, then click and hold the mouse and scroll over the grainy portion of the photo. This will be both smooth and sharpen the selected areas.
Try the "Blur" tool if your photo is still grainy. Click the "Filter" option again, then drag down to "Blur," and then "Smart Blur." Once you select "Smart Blur," another window will appear that will allow you to adjust sliders used to sharpen the photo. This step is the same as the "Reduce Noise" method, only with different effects. Once you have eliminated the graininess, click "OK" and save your picture.
Save your file multiple times as you work to avoid losing changes.