WORKING WITH IMAGES IN ADOBE PHOTOSHOP ~~~~~ by John Boretos, MP, NIHCC

Scan or Import the photo with a resolution and size matching the intended end use of the image, e.g., if the image is for web use (72 dpi) or for direct printing (300 dpi). In the case where significant modifications will be performed, then it its wise to start with the resolution somewhat higher since alterations can increase the file size thus reducing the ultimate quality (i.e., resolution). It is best to always convert the image to be smaller (not larger) after all operations are performed.

1. Open Adobe Photoshop. Bring up the Tools, Layers and History palettes if they do not come up automatically. Window > Show Tools, Widow > Show Layers, Widow > Show History etc. Press “d” on the keyboard to set foreground color to black. Press the “x” key to set a white background.

2. Open the image via File> Open> Look In >Open. Browsing in the Look In window can be confusing but by clicking on the down arrow on the right of the window, other files types that may apply to your image can be found. This takes some familiarity as to where you placed your images and gets even more confusing as your folders increase. If you are having difficulty finding an image that you may have recently filed in an unknown place, go to My Recent Documents to find your image. It will list the last 15 images that you have worked on.

3. Once the image is open, the first thing to do is to adjust the exposure. Refrain from using Image > Adjustments > Brightness/Contrast for this purpose. Instead opt for either the Curves adjustment or the Levels adjustment.

4. Curves Adjustment. Adjust the brightness and apparent color by going to >Image > Adjustments > Curves. Try to set the curves to the classic “S” shape with a toe, slope and shoulder. A good starting point is to set 5 equally spaced points along the curve starting at the very center of the diagonal line and clicking the “cross-hair”. Drag the lower two points to the right to yield an approximate 15 point difference in “in-put vs. out-put”. This establishes the toe of the curve. Do not move the center point. But move the upper two points to the left of the line the same degree. This then gives the starting point. Examine the highlights and the shadows. Things should look just about right and not too soft nor too much contrast. Proceed if OK.

5. Levels Adjustment. As an alternate to Curves, adjust RGB Levels for brightness and color by using Image > Adjust > Levels. The Levels Method is easier to master than using the Curves Adjustment described above and can produce near perfect results. A histogram appears with sliders along a horizontal bar. There are three points along the bar that can be adjusted. The one on the left represents the shadows and the one on the right is the highlights. The middle one is for the mid-tones. Bring the pointers on the right and left to the first peaks. Move the center pointer (the mid-tones) slightly each way to determine the best image improvement. You can see this happening on the image as you make adjustments. When satisfied, click OK.

6. Check the Layers on the Layers Palette to make certain there is only one showing. It should be highlighted in blue and labeled Background. There should be an eye and a brush icon to the left of a thumbnail photo of the layer.

7. Check the History Palette. At this point there should be only one entry shown. It should be >Open. The History Palette remembers recent operations performed and serves as a ready means of removing those operations if they do not satisfy you. Just click on them to gray them out. The default number of settings is twenty. This can be increased but is not recommended since the larger the history file, the more RAM is consumed. If you have plenty, add more.

8. Look the image over. There may still be discrepancies in the photo. If the whites are not as white as you need them to be, then go to the eyedropper in the Tools Palette and select this “Color Sampler Tool”. Using the eyedropper, click it on the white area in question. It will leave a cross-hair target in place. Go to Image > Adjust > Replace Color and slide the brightness bar in the direction that makes the best improvement for you. Not too much. You can observe this happening. Keep your eye on the other colors and subjects to make certain they are not affected. If other colors are affected, then you will need to use one of the Selection Tools to isolate the area you need to adjust.

9. Perform all other operations such as the use of filters essential to the final image.

10. Tweak a little. Consider Image > Adjust > Hue/Saturation and make final adjustments of the color and exposure. If you have objects that the color is not as intense as you want or if you want to change the color from say green to red, then click on colorize in the Hue/Saturation adjustment window and move the Hue slider until the effect is achieved.

11. If you are having conflicts with other objects in the photo that you do not want to have the color or brightness change, then you will need to go back to the image and “select” out the object or part of the image to be isolated, and then do the Hue/Saturation or Replace Color adjustments.

12. At this point you must merge all the layers. To do this go to Layers > Flatten Image. All the layers that you may have produced will be merged into one. The file size will be greatly reduced by flattening. If you think you may want to go back later and make changes to the layers, then make a second copy before hand. Otherwise, there is no going back.

13. If there are no other operations that you wish to perform, then sharpen the image by Filter > Sharpen > Un-sharp Mask. Do the sharpening only once and as the very last operation.

14. Now you may set the size of the image to match the printer’s resolution or converted it to a jpeg for use on the web. (see July 2003, Speedy E-Mail)

It may sound like a lot, but after a few tries, it will all become automatic to you. – Have fun and be creative.