Open your digital photo in Adobe Photoshop and save your file as a new name so you do not destroy the original file.
Locate “image” from the top menu selections and pull down to “image size.” Change the size of your document to more closely match your final stained glass project size. For example changing the 4-inch width of your 6-by-4-inch horizontal photo to 8 inches will create an 8-by-12-inch Photoshop document. You can cut off any extra image you do not want once you have printed your final stained glass pattern.
Posterize your photo to reduce the number of colors. Select “image” from the top menu, move down to the “adjustments” category arrow and choose “posterize" from the fly-out menu. Adjust the number for the color levels until you reach a pleasing image and color range to complement your glass.
Change the foreground color on the tool menu to a contrasting color from the rest of the tones in your image. Click the top square and slide the arrows on the rainbow in the color picker window until you are in a color range you desire. Take the selection tool (which is a circle in this window) and drag to the shade you want to use for the solder color, then click “OK.” This color will stand out just as the solder will in your final piece.
Select the magic wand from the tool menu. Adjust the “Tolerance” from the magic wand tool options to 30 as a starting point. You may want to adjust this number higher or lower to select as much or as little of a color area to break into your stained glass shapes.
While the desired color area is highlighted, select “Filter” from the top menu, move down to the “texture” category arrow and choose “stained glass” from the fly-out menu. Adjust the “cell size” and “border thickness” from the stained glass menu to desired glass shape sizes.
Continue to use the magic wand to select color areas, followed by the stained glass filter, until your entire photo is separated into shapes for your pattern.
Print your final pattern and trim any extra inches off of the paper to match the final size of your project.
Shade the entire back of your printed pattern with the grease pencil.
Select a piece of glass to cut. Flip your pattern back to printed side, place with shaded side down on glass and begin tracing the solder lines of your pattern onto your piece of glass.
Once all the pieces have been traced on a variety of glass colors and textures, you can cut your pieces with the glass cutter and begin soldering the pieces together using your printed pattern as a guide.