AboutScott Valentine Expertise Most anything about digital post processing (Photoshop, etc), effects, and image restoration, some technical information about digital imaging systems, light and electron microscopy, optical physics and image analysis. I can help with shooting basics, lighting setups, and getting the most out of your digital camera. I am also an 'expert' here for Photoshop (Computers/Technology > Software > Graphics Software > Photoshop).
I am currently writing a book for Adobe Press on composite artwork using Photoshop CS4.
Experience I've been an image analyst and advanced amateur photographer for over 6 years. I run an Adobe user group, focusing on digital media, and have lectured on digital image capture systems. Currently, I am an administrator for a rather large instructional Photoshop forum
Organizations Adobe User Groups, National Association of Photoshop Professionals, Advanced Imaging Specialists
Education/Credentials Bachelor of Physics, University of California, San Diego
Awards and Honors Winner: Best in Show and several category first place awards - Imaging Professionals of the Southwest Print Competition (multiple years)
Expert: Scott Valentine Date: 8/28/2007 Subject: colours and photos
Question Hey,
i have some lovely pictures i have taken of some children painting. What i want to do is turn the picture into black and white. Easy enough. I can do this... However. The children are painting with blue paint. What i would like to do is have the picture in black and white but have the paint remain blue in the picture. Is this possible, if so how. I have tried modifying the primary colours but it alters the colours in the whole picture.
please help! need to know asap.
I am using either Microsoft photo editor or nero photosnap image viewer. If i cant in these could you suggest a program i download and how to do it in that.
Answer Hi Erin,
What you request is fairly common, so there are several ways to go. Each of the techniques typically requires something more advanced than Microsoft Photo or Photosnap.
You will need either the Gimp or Photoshop Elements (or Photoshop, but that is an expensive solution). There may be other tools out there, so a Google search would be in order.
The idea is to use layers or masks, or some combination. Layers are like a stack of translucent images; you can choose your main photo as your base, then create a stack of images with different amounts of transparency to add or remove effects and information (like color). Masks apply to a specific layer and control individual pixel transparency - think of it as selectively erasing parts of a layer so you can see what's below.
In the case of selectively coloring, the two basic options are 1) to paint the color in on a new layer above the photo, and 2) to create a B&W duplicate above the color photo layer, and apply a mask to reveal the color below.
For the first option, you will need to use a 'blend mode' that allows the gray tones to show through the color. In Photoshop, that's called a "Color Blend" mode. It applies color based on gray value; black shows through completely, but white is completely colored.
For the second option, you will need to understand how masks work, and have good control over your mouse to control the brush strokes.
If you choose Photoshop Elements, you can also ask for help at http://photoshoptechniques.com or the main Adobe forums. The Gimp has a good community, too, but I don't know much about the different forums.
I hope this helps - If you have further questions, please feel free to ask!
