![]() Even with the simple function, I understand what it's saying, but I would not know how to perform it using simple selections and channel manipulation. Given all this undefined behaviour in the problem space itself, I'm sure Adobe Premiere and all the other professional video production tools contain very sophisticated chroma keying algorithms.Ĭan we even approximate the result of those algorithms using basic image manipulation, as found in Gimp? Or is any such endeavor bound to fail?Īlternatively, is there an open source Gimp plugin or separate program that can perform a good quality chroma keying on pictures?Įdit: Wikipedia's article gives an example of a simple function for green screen: rgb(r,g,b) -> rgba(r, min(g,b), b, A*(r+b)-B*g) and goes on to explain that modern algorithms can be much more complicated. For instance, the color that lies exactly between the key color (green in this case) and its exact opposite (which would be magenta in this case) is a perfect gray (by definition of opposite color.) Do we need to turn that shade of gray into semi-transparent magenta? What if it was an actual gray in the original picture? (Which is actually more likely.) I don't know the theoretical background behind chroma keying and I'm guessing it could be quite hairy. You can not turn a shade of green into semi-transparent red, and another shade of green into semi-transparent blue, just by fiddling with the magic wand, the color selection tool, or by copying a channel into a mask. The reason I posted this question is that all other questions and answers about this topic miss this crucial point. Meaning, if the key color is green, all greenish colors need to be substantially modified, in addition to having a suitable alpha channel added: Notice how this procedure is not merely adding an alpha channel it is changing all colors that lie in the same quadrant as the key color itself. If we look at what needs to be done (or approximated as far as possible, see below) it is the following: (Note: I don't know how to do it yet, this mockup was made starting from a stock transparent picture.) You can save the image now, but it will have jagged edges.Is it possible to apply chroma keying, meaning to remove a green (or blue.) screen background, using Gimp? (I happen to use Gimp, but I suppose an answer using Photoshop would be just as good, unless it's referencing a specific Photoshop plugin.) Now, press the Delete key on the keyboard to delete the background. If you’re having trouble with this, then click here for a more detailed tutorialĪdd Transparency to the image by clicking Layer, Transparency, Add Alpha Channel ![]() The image that you wish to keep should be in the “marching ants” line. Soon, you should see “marching ants” type of line around your main image I have added a subtle grey colored background to the image instead of the white background it previously had.Ĭlick the Fuzzy Select tool from the toolbox on the left side of the screenĬlick an even colored area on the image and then wait for it to process. You can download and install GIMP from their official website by clicking here Here, we will be removing the background of an image by using the Fuzzy Selection tool. png (non transparent), etc How To Remove Image Backgrounds Using GIMP? The aim is to demonstrate how you can remove background from a bitmap image that you want to use in your PowerPoint presentation. This is a tutorial on how to remove the background from an image using the free picture editing software GIMP. But, we can fix that by using a free and feature-rich image editing software called GIMP. ![]() Since this image is not a vector or a transparent PNG, it does not have a transparent background. ![]() The ‘white box’ is visible and there’s really no way to make it disappear from within PowerPoint. This is probably not the result you were looking for. However, what happens when you insert your chosen image in your presentation slide? There are websites like FPPT where you can get a nice looking template that suits your presentation. You can also get free to use images for your presentation. You don’t have to do everything yourself these days. When people make a professional looking presentation, they generally want everything to be presented properly. ![]()
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