| Author | Message | ||
     MJayne Member Username: Mjayne Post Number: 73 Registered: 10-2006 |
I have been trying to mask a sunrise sky area with tone range masking, however, I have not been able to keep out unwanted parts of the photo. The original sky area ended up with halos rather then the more gradual change that it should have and I already spent hours dusting this from a dirty scan so don't want to repeat it. I have a couple questions: If the blur radius is set for 35, does that mean that it only blurs 35 pixs back into the mask, from the edge of the mask or does it blur outward also? Is there an easy way to edit the edges of my tone range mask sky area to keep out the unwanted areas on the edges of the clouds and tops of the mountains. The cloud edges are so feathered. When I go in an subtract with the similar pix option the edges look bad and the mask has a different density. I want to composite just the good sky backround from another photo, which is the same photo only it is 346 mgs rather than 349 mgs from a drum scan. I'm thinking that it wil not be exactly pixel to pixel. Does anyone know how to handle this so my edges will be good for an enlargement? | ||
| Jonathan Sachs Member Username: Jsachs Post Number: 791 Registered: 08-2002 |
Usually the best way to mask a complicated region like the one you are working on is to paint around the edge using the Mask Paint tool and selecting the Similar Pixels (Tracked) option. Paint carefully around the edge from one side or the other - whichever is more even-toned. The brush will only paint the mask where pixels are similar (based on the threshold slider) to the one under the center of the brush. Once you paint around the edge, you can fill in the rest with a large diameter normal brush or the freehand outline mask tool. The Composite transformation lets you rotate, translate and/or resize the overlay image by using 2-point (shift/rotate/scale) and setting alignment points as necessary. See the manual or white papers for details, but basically the overlay image is adjusted as necessary to bring both sets of alignment points into coincidence. Jonathan Sachs Digital Light & Color | ||
| den Member Username: Den Post Number: 288 Registered: 03-2006 |
To remove halos inadvertedly generated by a mask, try a 'transition zone mask' with the HSV ColorCurves transform to reduce the halo's contrast and/or saturation... Explanation: Mask images comprise of three image areas: (1) solid 0% black; (2) transition zone, 1%->99% grays; and (3) solid 100% white. The transition zone can be symmetrical, i.e., the gradient from the 50% tone to white, 100%, is the same as the gradient from the 50% tone to black, 0%; can be used inverted under ideal conditions without generating halos; and can be generated by the Mask Tool - Blur and/or Feather options. The transition zone can also be asymmetrical, i.e., the gradient from the 50% tone to white, 100%, is different than the gradient from the 50% tone to black, 0%; usually cannot be used 'inverted' without the generation of halos; and can be generated by creating tone range masks. To form a transition zone mask: (1) click on a mask image and open the Mask Tool - BrightnessCurve; (2) form and 'lower-left' Apply - Add, a Smooth or Broken Line curve = [0,0], [50,100], [100,0]; and (3) click OK. | ||
| Elie Dinur Member Username: Elied Post Number: 222 Registered: 07-2003 |
den - That's something I never thought of, making a mask of a mask. What a great idea, it opens all sorts of possibilities. U DA MAN! | ||
| den Member Username: Den Post Number: 289 Registered: 03-2006 |
I cannot take credit here as the 'transition zone mask' is a variation [one of the possibilities] of the 4th Mask concept originally proposed by BobW a couple of years ago for use with 3Tone Range masks... | ||
| MJayne Member Username: Mjayne Post Number: 74 Registered: 10-2006 |
Thank you Jon and Den for your suggestions. Jonathan, I will try sticking real close to the edges with the similar pixels. I have found this to be painstaking (compared to tone range Masks) and my edges never look right, however maybe I will try it in a small area and then add to it with the combine masks. Den, I read a little of Bob's 4th Mask Thread, however I think I need to read up more on this "transition zone mask" as I am a little confused and don't know how I would apply it to my image. Are you opening a Mask and adding the curve to the mask to make the solid masked areas more transparent? I need to make a new mask as I didn't save it and actually don't know how the halos appeared. I may have gone into PS first and messed around in Lab trying to get a little more green into the pic. | ||
| den Member Username: Den Post Number: 290 Registered: 03-2006 |
A 'Transition Zone Mask' is derived from an existing mask image so if there is not one available, this approach will not work... | ||
| MJayne Member Username: Mjayne Post Number: 75 Registered: 10-2006 |
Thank you Den for the info. So that would mean that I would need to have the mask that actually caused the halo? I can make a new one. | ||
| den Member Username: Den Post Number: 291 Registered: 03-2006 |
YES... if a 'transition zone mask' ["mask of a mask"...ElieD] is needed to remove an inadvertent halo, it should be created from the 'mask image' that generated the halo. Another approach though dependent upon one's artistry: Create an image version such that the halo image areas have reduced contrast and/or saturation that with blend with the 'starting image's' immediate surrounding image content, then one-to-clone back into the 'starting image'... ignore non-halo immediate image areas in the created image version as they may take on unusual appearances... but then you are not interested in these areas anyway. | ||
| Bob Walker Member Username: Rwalkernm Post Number: 132 Registered: 06-2004 |
MJayne, Actually, I think you need to have saved (or be able to rebuild) two masks. If you want the transition mask between midtones and highlights, for example, then you need both those masks. Use PWP's mask tool to combine (in add mode) the two masks. Then invert the result and you have the transition zone mask. The sum of the transition zone mask, and the two original masks, is pure white. The transition zone mask is light wherever there are pixels that were not captured in either of the two original masks. When you make one of den's 3-tone masks, halos are produced by the blurring step, and will have a thickness in the same ballpark as the blur radius that was used. The transition mask helps to identify and process just the part of the image where these halos occur. BobW | ||
| MJayne Member Username: Mjayne Post Number: 76 Registered: 10-2006 |
Thanks guys for your time and help, I'm going to try to work on this tomorrow night and maybe it will sink in a little better. I think I have some limited understanding of the transition zone mask now. I have to take things slow,(duh) and have very limited time to work on my photos. I am also going to go over all the old blogs on "blurring". |
