Photo 11: Introduction to Digital Imaging
Instructor: Sue Leith, sleith@csus.edu Office Hours Monday 1 -2 MRP 2011
Exercise: Hand-coloring a color image
Drag the HC image to your desktop and open in Photoshop
1. Use the measure and crop tool to straighten the image, keeping as much of the original image as possible. Take a snapshot and name it “straighten”.
2. Use an adjustment layer to make the image a custom b&w. Name the adjustment layer “black and white”. Take a snapshot and name it “black and white” also.
3. Select the yellow portion of the flowers and the green leaves to the right of the frame. Don’t forget to feather your selection after it’s made: Select > Feather > about 2 or 3 pixels.
4. Save your selection and name it flowers and leaves.
5. Paint on the mask of the adjustment layer to bring back full color to the flowers and leaves you just selected. Take a snapshot and name it “color”.
6. Bring back 50% of the color to the table.
Optional and more challenging
7. Change the colors of the flowers only.
Save as yourname.color.psd and drop in the drop box for your class section.
How to do this exercise
1. The measure tool is under the eyedropper. To use it, draw a line then go to Image > Rotate Canvas > Arbitrary and click ok. Next use your crop tool, pulling on the anchor points at the side, to crop out the edges.
To take a snapshot, in the history palette, click the small icon of the camera to the left of the trash. To name a snapshot double click on the name and type in what you want. Once you close the image all history and snapshots will be deleted – you may not access them anymore after closing the image.
2. Make sure your channels panel is visible (Window > Channels). Click on the word red, then green, then blue to choose which you like best. Make sure to click back on the RGB at the top after deciding and before moving on to the next step.
Click on the adjustment layer icon in the bottom of the layers palette or Layer > New Adjustment Layer > Channel Mixer and check the Monochrome box at the bottom of the dialog box. Move the sliders – I used 40 Red, 10 Green, and 50 blue for my mix with this image.
3. Make sure you are on the background layer where the flowers exist and turn off the eyeball on the channel mixer layer so you can see the color. You cannot select the flowers if you are on the channel mixer layer. Use the eyedropper to click on the yellow of the flowers then go to Select > Color and using a combination of the eyedropper with the + sign and the fuzzy slider you should be able to get a pretty good selection. Then, to make your selection even better use Select > Modify > Smooth (about 5 pixels). You may have to do smooth a couple of times. Then, Select > Modify > Expand (about 5 or 6 pixels). Once the yellow is selected use your magic wand making sure you check the box Add To Selection in the options bar (you may also have to change the tolerance number – smaller number selects less) and click around in the green leaves until they are selected.
4. Select > Save Selection.
5. Turn the eyeball back on for the Channel Mixer layer and make sure you are working on that layer – the one you named black and white. To see how well you’re doing use the shortcut Command H to hide your selection – it should still be active – and just paint. If you missed a few spots, deselect Select > Deselect or command D and carefully, still working on the mask, use a small brush to color them in. Don’t forget you can zoom in and out (command + or command -) to see exactly what you’re doing. You may also hold down option and click on the mask to see areas that may need fixing. If you make a mistake and get color where you don’t want it, switch to white to fix.
6. Grab the brush tool and change the opacity in the options bar to 50%. Make sure you’re still working on the channel mixer mask in the layers palette and paint the table. If you option click on your mask after doing this the mask should be black where you revealed all the flower and leave color and gray where you revealed half the table color.