Chroma Key Masking Question

[Craig]

Can I use the attached green screen jpeg as a mask in PTE?  I am able to use image editors (such as GIMP) to replace the bright green with pure white, but then my own images do not show through the pure white to serve as background.

I must be overlooking a simple solution and appreciate any thoughts.  Thanks.

-Craig

 

[Lin Evans]

Hi Craig,

You can, but it won't do what you expect. Masks in all software have two main possibilities, transparency to objects outside the mask which is obtained by black and white of which white is transparent to the object within the mask and let's it show through while black is transparent to what is outside the mask. You can also use a PNG file for a mask where you use transparency to see things outside the mask.

PTE has chroma key extraction for greenscreen video, but doesn't use chromakey for still images. If you can explain what you want to see where the green is and what will be going on where the road is, I'll help you sort it out quickly. After re-reading what you said above, I suspect it's just a misunderstanding of how to set up your mask...

If you will tell me what precisely you are trying to achieve I'll show you how to do it...

Best regards,

Lin

[Craig]

1 hour ago, Lin Evans said:

Hi Craig,

You can, but it won't do what you expect. Masks in all software have two main possibilities, transparency to objects outside the mask which is obtained by black and white of which white is transparent to the object within the mask and let's it show through while black is transparent to what is outside the mask. You can also use a PNG file for a mask where you use transparency to see things outside the mask.

PTE has chroma key extraction for greenscreen video, but doesn't use chromakey for still images. If you can explain what you want to see where the green is and what will be going on where the road is, I'll help you sort it out quickly. After re-reading what you said above, I suspect it's just a misunderstanding of how to set up your mask...

If you will tell me what precisely you are trying to achieve I'll show you how to do it...

Best regards,

Lin

Thanks so much, Lin.  Yes, as you said, I also suspect this is a misunderstanding of how to set up my mask.  What I would like is simply to be able to place a single image where the bright green is located and perhaps to pan and zoom toward that image to create the effect of driving down the road.  If I could learn the solution to this question, I think I could apply the principle to various other effects in PTE.

Does this help answer your question about what I am trying to achieve?

Thanks again...I appreciate your help!

-Craig

[Lin Evans]

Sure, that's an easy one. Give me a few minutes and I'll send an example for you...

L

[Lin Evans]

O.K. here's a quick and dirty example, but I think you will be able to see how it works. Click the link below and download the zipped PTE file. Extract the elements into a folder and load the PTE file into PicturesToExe.

In essence, I took your green and turned to to white and painted the rest of that black to make the mask. Then I took the same image and overlaid it on a transparency and made the part which was green, transparent. Then that goes under the mask and mask rectangle and the image you want to appear behind the road goes inside the mask...

http://www.lin-evans.org/sample/maskexample.zip

Another way to accomplish the same thing without using a mask at all would be just to make the part which was green transparent and put in on the layer above the image you want to appear in the background - no real need for creating the complexity of the mask. There are multiple ways to do things usually... Try just taking the image with the transparency above the road and using it with your choice of background... should work perfectly...

Let me know if you have questions.

By the way - here's a bunch of Youtube tutorials on using Gimp to make a transparent background, etc.

https://www.youtube.com/results?search_query=make+background+transparent+gimp

Best regards,

Lin

[Craig]

On 6/11/2016 at 7:36 PM, Lin Evans said:

O.K. here's a quick and dirty example, but I think you will be able to see how it works. Click the link below and download the zipped PTE file. Extract the elements into a folder and load the PTE file into PicturesToExe.

In essence, I took your green and turned to to white and painted the rest of that black to make the mask. Then I took the same image and overlaid it on a transparency and made the part which was green, transparent. Then that goes under the mask and mask rectangle and the image you want to appear behind the road goes inside the mask...

http://www.lin-evans.org/sample/maskexample.zip

Another way to accomplish the same thing without using a mask at all would be just to make the part which was green transparent and put in on the layer above the image you want to appear in the background - no real need for creating the complexity of the mask. There are multiple ways to do things usually... Try just taking the image with the transparency above the road and using it with your choice of background... should work perfectly...

Let me know if you have questions.

Best regards,

Lin

Lin, your advice was invaluable.  I had neglected to add the B&W layer in the mask container, which is why my image kept showing through the entire (transparent) image to my great frustration.  Your sample was invaluable and I learned an important lesson in Masks 101!  Now, I look forward to proceeding further in my experience with PTE, particularly as we await the new beta version.

Thanks so much!

-Craig