Most of my authors supply photographs to include in their books. Since I have grown familiar with Photoshop (elements 9 now), I enjoy optimizing them for inclusion. There are several things to consider:
- 1. The resolution of the picture should be 300 dpi in the final size on the page. That is easily done by using the image size instruction, but it requires advance knowledge of the desired size on the page of the final layout. It doesn’t work to just drag a corner on the page because the pixels per inch changes as the size is changed. So the final resolution needs to be set at layout time. I usually leave the pictures at their original resolution until just before inserting in the book.
- 2. Ancient pictures may have tears or mold spots. Much of this can be fixed with the clone tool, but it is a tedious process.
- 3. Contrast and brightness can often be improved. I use the levels command (ctrl L) to do this, stretching the range of pixels to go from full dark to full white. Then, for inclusion in a book I adjust the output levels so the whitest white will become a little grey–if the sky goes gradually to full white in the book there will be contours where the dots of the lightest grey transition to full white.
- 4. If a color picture is to be converted to grayscale, I use the color control (ctrl U) to bring the overall saturation to zero and, before finishing, work with the colors one-by-one to adjust the lightness. In that way the overall contrast of the final picture can be improved. If you make, say, the red color full white then all the areas in the picture that were red will change from some shade ogray to white. Likewise with the yellow, green, cyan, blue,and magenta. The result can be a much more dramatic grayscale picture that a simple conversion,
All of these steps take time, but they are among the ‘funnest’ activities of preparing a layout.