Step One
The first step is to make sure the teeth aren’t colored because of a color cast in the photo. This can come from mixed lighting or improper settings of white balance. We’re going to do this using the Levels tool. Go to “Image > Adjustments > Levels” or hit “CTRL + L”. In each individual layer, drag the sliders until they meet with the main group of dotted pixels in the histogram.
The original image
Red Channel adjusted to 228.
Green Channel adjusted to 179
Blue Channel adjusted to 132
As you can see, removing the color cast has already made the teeth appear much whiter and healthier, along with giving the skin a nicer tone. We can now put on the finishing touches towards whitening the teeth.
The color cast has been removed
Step Two
Now that the overall white balance of the image has been corrected to some degree, we can start on the tooth-specific whitening. Enter “quick mask” mode by hitting “Q”. This mode is a way of making a selection using the brush tools. Select a soft, round brush and hit “D” to make sure your primary color is 100% black. Brush over the teeth using black, and hit “X” to switch to white
if you make a mistake. Brushing in white applies the mask, brushing in white removes it. You can use shades of gray for a more transparent effect. Make sure you avoid the gums, lips and shadows!
Don't worry, it's meant to be like this!
After masking, you should have all the teeth you want to whiten covered in transparent red.
Step Three
Hit “Q” again to exit quick mask mode. You’ll now have a selection of the teeth, ready to be edited without brightening the rest of the face, gums, or lips.
The teeth are selected, ready for editing
Step Four
Now that you have the teeth selected, it’s time to remove the yellow color. Create a new layer (CTRL + SHIFT + N) and fill it with pure white. Change the layer’s blending mode to “color”, and reduce the opacity to around 30%.
The layer before using blend modes
The layer after blend modes
By setting a pure-white layer to the “color” blend mode, we’ve told Photoshop to strip the layers beneath it of color. Reducing the opacity to 30% means it takes off about 30% of the teeth’s color, so that our eyes cannot perceive the yellow tint.
Step Five
Now we must brighten the teeth, to match the edit to remove color we just made. Reselect the mask we already made by CTRL + clicking on the thumbnail in the layer palette, and go to “Layer > New Adjustment Layer > Brightness / Contrast…”. This step is more up to the individual image, but I recommend you adjust the brightness slider up until you see pure white, then taking it down 5%.
Take the contrast down in order to further reduce any yellowing effects.
The teeth now have a natural bright sheen
The teeth look healthier and whiter than before
That’s it! If you have any further questions, post them in the comments.
Última edición por ockre el Vie Ago 29, 2008 3:43 am, editado 1 vez