Edge Effects in Photoshop
1. Open an image. Make a rectangular selection staying about a half inch from all edges of the image. Or use a selection tool to make an irregular selection.
2. Switch to Quick Mask Mode. Your selection will turn red.
3. Go to Filter > Brush Strokes > Spatter Adjust the preview window so you can see the edge of your mask and move the sliders until you are pleased with the effect. I used radius:20 and smoothness: 4.
4. Exit Quick Mask Mode. You will see your selection without the red.
5. Invert the selection Select>Inverse (Shift+Ctrl+I). 6. Fill with white or whatever color you want for your edges (Alt+Backspace).
Try this same technique (No. 3, above) with these filters for other edge effects, or experiment! Filter > Distort > Ocean Ripple Filter > Distort > Glass Filter > Blur > Gaussian Blur (10-20 pixels) followed by Filter > Pixelate > Color Halftone Filter > Blur > Gaussian Blur (10-20 pixels) followed by Filter > Pixelate > Crystallize Filter > Blur > Gaussian Blur (10-20 pixels) followed by Filter > Artistic > Dry Brush Filter > Blur > Gaussian Blur (10-20 pixels) followed by Filter > Artistic > Rough Pastel Filter > Blur > Gaussian Blur (10-20 pixels) followed by Filter > Artistic > Palette Knife Filter > Blur > Gaussian Blur (10-20 pixels) followed by Filter > Pixelate > Mosaic Filter > Blur > Gaussian Blur (10-20 pixels) followed by Image > Adjust > Posterize (5-10) Filter > Stylize > Diffuse (apply multiple times)
Palette Knife
Color Halftone