All I mean is that you don't need my tools to do things in PS6. You can do them without. Certainly you should learn from them in any way you find helpful.
I would be glad to see what you've put together when you are done.
Paul and Richard,
After a first WOW! experience with Paul’s technique, Richard’s comment on the need for both backgrounds to be ABSOLUTELY identical became obvious and my idea to move the microscope stage to an object-free position impractical. The reason is simple: the “dirt” content of the fields is not the same (dirt is a composite of dust, staining remnants and thickness variations of mounting medium).
So I set about to circumvent the problem and came up with the following solution:
-Lasso a portion of background
-Lasso another portion of background
and repeat the same a few times , merge all new layers and apply Paul’s technique.
The few remaining blobs are easy to paint over.
See attachment for result.
So that is all very nice but time consuming and I risked my hand at recording the whole process in PS 6.The action works beautifully on the image used for recording but eats up nearly everything on another(but similar image)!
See for yourselves
If you are working on the same image every time this might work, but the problem is you may be trying to automate too much of the series. For example, if you are trying to do as described earlier, you might want to make a manual selection and then automate select similar, delete, and assign this to a keystroke. You really can only make useful actions of things that are ultimately repetetive...meaning not only that you go through the same steps, but that you go through the same steps applied the *same way* to every image. My guess from looking at that image is that these things are not shaped exactly the same way every time. That being the case you cannot automate the selection of shape.
Depending on what really needs to be selected and the true difference between the images and exposures, you *may* be able to automate more of this (for example, if all the objects will be darker than the background, if they will all be a particular range of reds, whatever). In looking over the text for the action, it seemed that there were unnecessary steps. If using PS6, you would want to sub out the actual selection (Set Selection
Points: point list
point: 23.977 inches, 18.737 inches
point: 23.977 inches, 18.737 inches
point: 23.684 inches, 18.61 inches
point: 23.644 inches, 18.528 inches
point: 23.601 inches, 18.443 inches
point: 23.561 inches, 18.361 inches
With Anti-alias -- which selects exactly the same image area every time based on coordinates) with a Stop, that allows you to do something else (make a manual selection) before continuing (by pressing play). In elements, recording would have to be done so all the parts were separate actions with separate prompts for play.
That help? If I had several images to compare, I might come up with something more clear, but I have only the one image with nothing to compare.
Claude, I can't help with the action (I don't have PS6) but I was able to generate a mask thus:
1. Duplicate the background layer
2. Add a Hue/Saturation layer
>> edit the "reds" and "magentas" to have 100% saturation
3. Use HP to add a curve
>> set the graph to "levels of grey" mode
>> activate the pencil (click the "pencil" icon)
>> click at "input 0, output 0"
>> shift-click at "input 170, output 0"
>> shift-click at "input 170, output 255"
>> shift-click at "input 255, output 255"
(the 170 value is a threshold; you might want to experiment with higher/lower values to find a "better" value and to get a feel for what this curve is doing).
4. Use the HP3 to add a Selective Color layer
>> set the method to "absolute"
>> for the "reds", "magentas" and "blues" set the black slider to +100%
5. Hide the visibility of the background layer; select the background copy layer, and then "merge visible"
6. Reduce the opacity of the copy layer and re-enable the visibility of the background layer.
7. Use a hard white brush to paint over the black blobs in the "dirt" area (don't worry about the other colours, e.g. cyan)
8. Once you've finished cleaning up, use "Drop Black" and "Commit Transparency" to finalise the mask.
Hope I've explained this OK!
I did try using a Threshold Adjustment Layer (which is where I derived the 170 value from), but I found using the curve gives better results.
Thank you for an illuminating answer.
2-By the way can Play and Stop be assigned to a keystroke?
3-What is the effect of anti aliasing in general and in particular for a selection?
Thank you too.
Fumbling further afield, I think I found a quicker way to deal with the BG:
-Set background color to white
-Lasso BG sample
-ShiftDrag any further number of BG samples(to catch as many variations of "dirt" as possible)
-Paint remaining blobs
This cannot be automated but I think it is faster than anything else.
I really must thank you again after trying your last suggestion.
It is a bit involved for my purpose of treating quickly a sometimes large number of images but it also throws a light in the(for me) still dusky lanes of PE and HPE.
I could not have come to the method mentionned in my last post without yours and Richard's suggestions.
glad I could help, and I have to say I've found the images of yours quite intriguing to look at.
I find masking does play a big part in image manipulation, and the "clear/drop" HP tools are invaluable in mask generation -- all you have to do is manipulate the image to get to the point where you can use them and you've got your mask. This is where playing around with the other tools helps. Sometimes you get a weird or wacky result, which may be useless in the final image -- but it could be a big help in mask generation! For example the curve I suggested you create is inappropriate for the final image because it destroys detail. However, the simplification of the image it produces makes it ideal for mask generation.
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