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Q. What does "remapping" mean?
Asked by Brian Griffiths
(K=225) on 8/20/2009
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I was watching a video tutorial on Photoshop in which the guy narrating it slides the hightlight slider in Levels to the left and says something about "remapping" the lighter pixels in the image. I've been all over trying to find a definition for "remapping" but to no luck, though lots of people seem to use it. Any help?
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Saad Salem
(K=62435) - Comment Date 8/21/2009
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Hi Brain,
I will try to explain remapping in my bad English and hope you will get something of it,
remapping is a process by which you give a different value to the pixels in your shot,whether they are white or black,to understand it perfectly you have to try it with a shot and open its histogram at the same time.
any adjusting of the mid tones ,that is in the middle of the histogram,will change the values of the mid tones details ,
adjusting the the highlights value,ie shifting the values of the most white values in the shot ,will shift their values to a lesser value than 255.by sliding the most upper value to the right.this is called remapping because you give values lesser than what they are,it affect all the highlights in your shot by giving them new value,
The same is applied to the shadows,their maximum value is zero,and that for the pure black,if you slide the values to the left ,you will remaps the values of the blacks to a new values of more than zero,and this also affect all the blacks in your shot by gaining a new value,this is also a remaping of the black values.
I hope you will get some thing from this note.
be well.
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Saad Salem
(K=62435) - Comment Date 8/21/2009
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Sorry Brain ,I have mixed my left and right with that of the monitor,
this is a Corrected Version,
remapping is a process by which you give a different value to the pixels in your shot,whether they are white or black or at midtones range.
to understand it perfectly you have to try it with a shot and open its histogram at the same time.
any adjusting of the mid tones ,that is in the middle of the histogram,will change the values of the mid tones details ,and hence their pixels value.
adjusting the the highlights value,i-e shifting the values of the most white values in the shot (in histo it is situated at the most right and having the upper value of 255) ,will shift their values to a lesser value than 255.(they became darker )by sliding the most upper value towards the left(by moving the slider to the left).this is called remapping because you assign a new values which is lesser than what they have at the original shot ,it affect all the highlights in your shot by giving them new value,this is a pure remapping.
The same is applied to the shadows,their maximum value is zero,(situated at the extreme left of the histo)and that is for the pure black,if you slide the values to the Right( by moving the slider to the right) ,you will remaps the values of the blacks to a new values of more than zero,(they became lighter shifting towards the white value)and this also affect all the blacks in your shot by gaining a new value,this is also a remapping of the black values.because in this process you are taking a pixel and changing its value by shifting it towards the left or right= REMAPPING.
we usually remap the midtones during the correction of levels,and I myself very rarely adjust the pure black or whit values.
I hope you will get some thing from this note.
be well.
Saad.
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Brian Griffiths
(K=225) - Comment Date 9/1/2009
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Saad,
Thanks so much for this. So it's pretty much giving new values to pixels. Thanks so much!
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