Masking improvements

[rah50]

Would it be possible to add masking tools where you could select just the center or corners of image? Many times you only want to touch the center or corners, but not both. Of course, they would need to expand out incrementally as well.

Just a thought,

Bob

[admin]

Hi Bob,

Can I ask in which cases you would use this, just so i get an idea of what to code? I'd be happy to include the functionality in 1.1, but am not entirely sure what you mean (or what you would use this for?).

Cheers,

[admin]

I added a circle mask generator ('Radius' option) in the Mask Auto generator. Use the threshold parameter to vary the radius. Circle radius is expressed as a percentage width or height, whichever is larger.
Selecting the corners only is just a matter of clicking the invert button.

You can find the feature in the latest 1.1.86 Beta build in the download section.

Is this what you're after Bob?

Cheers,

[rah50]

Thanks Ivo:

That's not quite what I was looking for, but I think it could be useful in something like the Sharp function where you have the highest S/N in the center.

I was thinking more of having that function available AFTER you do a mask where just stars are selected as in the Repair and Heal functions, as problems are usually just in the corners.

I've been focusing my use of Startools mostly in the Repair function where it does a great job of rounding my stars. I have a Tak BRC-250 which tends to give squarish stars due to the heavy secondary vanes. However, the Repair function tends to combine too many closely paired stars. Is there any way to minimize this more while still doing a great job of rounding? I've been using redistribute, 8x etc which gives beautiful round stars, although with the combining problems. I think running Magic first helps as it shrinks the stars and provides more space between the pairs. I thought up-scaling the image might help, but my 16803 files are almost too big for Startools already. Any suggestions?

Thanks,

Bob

[admin]

Thanks Ivo:

That's not quite what I was looking for, but I think it could be useful in something like the Sharp function where you have the highest S/N in the center.

I was thinking more of having that function available AFTER you do a mask where just stars are selected as in the Repair and Heal functions, as problems are usually just in the corners.

I've been focusing my use of Startools mostly in the Repair function where it does a great job of rounding my stars. I have a Tak BRC-250 which tends to give squarish stars due to the heavy secondary vanes. However, the Repair function tends to combine too many closely paired stars. Is there any way to minimize this more while still doing a great job of rounding? I've been using redistribute, 8x etc which gives beautiful round stars, although with the combining problems. I think running Magic first helps as it shrinks the stars and provides more space between the pairs. I thought up-scaling the image might help, but my 16803 files are almost too big for Startools already. Any suggestions?

Thanks,

Bob

Gotcha. I believe the new feature may actually help here;

• Round the stars as normal, ignore any erroneously 'lumped together' stars in the center.
• Create a mask with a circle using new new feature. Make it the size of whatever area of the image is unaffected (e.g. leaving the corners non-green).
• Launch the Layer module, click Und2F ('Copy Undo Buffer to Foreground'). This will copy the original unrounded image to the foreground layer.
• You will now see a composite of the rounded and non-rounded image with Stars near the edges/corners rounded.
• You might want to bump up the Mask Fuzz parameter to make the two images transition smoothly from non-rounded to rounded.
• You may now want to apply the 'Warp' algorithm to the rest of the image if needed. The 'Warp' algorithm is less prone to the 'lumping' together phenomenon, but is only effective when stars are at the very least oval and still have a well defined core. The 'Redistribute' algorithm is very much a 'last resort' algorithm for severe distortions. Applying them both gives you the best of both worlds.

By far the best (but most laborious) method however, is to touch up the mask in such a way that stars are separated by at least one pixel, so that 'lumping' will not occur. To do this, put the Brush Mode into 'Single Pixel' mode and zoom into the problematic region. Clicking on the mask will toggle single pixels on and off. Doing this, separate the stars by at least one pixel - a star's pixel is considered separated from another if an 'on' (green) pixel from that star is not directly left, right, up or down from an 'on' (green) pixel belonging to another (i.e. diagonally adjacent pixels are allowed). Be sure to up the 'Grow Mask' parameter by at least 1 pixel so that the starlight of any separator pixels we turned off is still erased when the new stars are composited.

Does this help with your problem?