Replacing a background color / image

bhawk · Post by **bhawk** » Sun May 06, 2007 11:19 pm

Is there another way to replace a background (solid color) / extract an object other than using the object extract tool? I currently have Photo Impact 10 and the extractor is not doing a good enough job for what I need.

Thanks in advance

fortemac · Post by **fortemac** » Mon May 07, 2007 4:16 am

Use the Bezier Curve tool (2nd tool going down on the lefthand side in PI12, 4th selection). Make sure the drawing tool (4th tool on bottom row of tools) is set to the bezier curve. Click around the object connecting the last click to the first. Then click on the pick tool. You can now select your object and cut it out or you can invert the selection and delete the surrounding areas.

heinz-oz · Post by **heinz-oz** » Mon May 07, 2007 8:55 am

Not knowing your image, it's hard to recommend anything. Generally I prefer to use the masking tool to extract an object from an image. You can find a tutorial on creating and using masks here but a bit of imagination is still needed.http://wwell.net/tutorials/pi8/masks/
The tut is for PI 8 but I have done it in 10 and now use 12. The differences are minimal.

bhawk · Post by **bhawk** » Mon May 07, 2007 11:14 pm

Thanks for both of your suggestions. The specific problem I have is extracting a person and the hair is the primary problem. The result is either leaving the background behind the hair or cutting out hair that I want in the image. The background is a solid color...is there a way to just delete specific colors?

heinz-oz · Post by **heinz-oz** » Mon May 07, 2007 11:38 pm

Make the background color transparent. It's commonly used with blue/green screening. Hair is always a problem. Even high quality TV broadcasts often show a distinctive color cast, either blue or green, when the hair of the subject is frizzy.

bhawk · Post by **bhawk** » Mon May 07, 2007 11:53 pm

heinz-oz wrote:Make the background color transparent. It's commonly used with blue/green screening. Hair is always a problem. Even high quality TV broadcasts often show a distinctive color cast, either blue or green, when the hair of the subject is frizzy.

Thanks. Is there a trick to it....when I do that it makes my entire image transparent.

heinz-oz · Post by **heinz-oz** » Tue May 08, 2007 12:52 am

You have to save the image to a format which retains transparency, like gif (limited color depth) or png or tga.

For video work you can also chroma key the background. That's how TV broadcasts are done.

Where do you want to use the image? If on a web page, save to gif or png and make sure that transparency is selected. Select the color of the background to be transparent in the options and you are done.

bhawk · Post by **bhawk** » Tue May 08, 2007 2:46 pm

Thanks! I have mainly worked with video editing. Editing photos is taking a little more effort to develop my skills than I thought...it is not as intuitive to me as I imagined.

I am trying to get the same effect as the chroma key in video. I want to use it for portraits and then apply digital backgrounds to the shots. I know .png degrades the quality of the image....what about .gif or .tga? I do not want to loose any quality. Does RAW retain transparancy?

You and I have the same video camera by the way...gs400. I have really enjoyed it the last 2 years...it has been handy to have a video camera that takes good stills as well. Now there are a lot of cameras out there with this capability.

Thanks for your help....Boyd

Bobm03 · Post by **Bobm03** » Tue May 08, 2007 9:28 pm

bhawk wrote: ~~~I am trying to get the same effect as the chroma key in video. I want to use it for portraits and then apply digital backgrounds to the shots.

Like this?

The head & t-shirt became an object using the lasso and magic wand selection tools. The object was placed onto a special background I use for photo IDs and merged with a soft edge.

The original photo was a 5 megapixel image. The final image for my purposes is 480 x 640.

heinz-oz · Post by **heinz-oz** » Tue May 08, 2007 11:20 pm

bhawk wrote:Thanks! I have mainly worked with video editing. Editing photos is taking a little more effort to develop my skills than I thought...it is not as intuitive to me as I imagined.

I am trying to get the same effect as the chroma key in video. I want to use it for portraits and then apply digital backgrounds to the shots. I know .png degrades the quality of the image....what about .gif or .tga? I do not want to loose any quality. Does RAW retain transparancy?

You and I have the same video camera by the way...gs400. I have really enjoyed it the last 2 years...it has been handy to have a video camera that takes good stills as well. Now there are a lot of cameras out there with this capability.

Thanks for your help....Boyd

What makes you say png degrades the quality? Any alterations to an already compressed image and subsequent saving to another compressed format again will lose some quality.
You can't use RAW images for anything but conversion to another format.
Gif will definitely alter the quality of your image because maximum color depth is 256 colors

If you only need this as an image, stay in Uleads proprietary format ufo until you are done. That will keep generation loss to a minimum.

I rarely use my GS400 for stills although they are not bad. The quality I get with my compact Canon S45 (4 MP) is much better and the Canon EOS 350D is better still.

From what I can gather you are just preparing photos which are not intended for video, right?