Understanding Levels and Curves

I've read some tutorials on this subject, but I'm hoping someone can help me conclude this learning chapter hopefully by a tutorial or explination on how levels and curves work and what and how to read them. So far from what I know with levels you have a white slider and a black slider I don't know how the peaks and valleys work that you see in the levels window I also don't know what the middle slider represents. As for curves I'd like to know how to use and how to read and tweak a curve what it does.

Ok that tutorial loads all the way for me. Although the business of moving values is explained Ok in there - there are a number of basic problems, and bad practice demonstrated in the tutorial, and its not one I would recommend …
1: The guy has made three moves, two Curves and a Levels - extremely destructive to the image . Where a single Curve could have done the same visually, with much less damage. In other words, he obviously doesn't realise what basic things like the endpoints of the curve do. Levels although it uses different MATH, is reproduceable in Curves very precisely. In practice, in terms of overall image EFFECT, there's really no point at all in using Levels if you know how to use Curves properly. Think of Levels as a poor mans, slightly easier to understand, Curves.
2: He has duplicated pixels instead of using Adjustment Layers, pretty thick and generates larger files.
3: He doesn't seem to know that you can place curve points automatically, and as a result doesn't explain how to do this.
I did some searching for you, trying to find something better -
http://www.youtube.com/watch?v=egwF0WWqHuE&feature=related - In 2 parts, yeah its Kloskowski, but he is explaining it quite well, especially the basic theory
http://vimeo.com/46703100 I quite liked this one, ignore all the other stuff, he's going though curves it in a way which might help it to dawn.

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Levels, Exposure, Curves - another explanation attempt

The exposure slider in Aperture does pretty much the same as moving the right bottom sliders in Levels. One difference is that one naturally can move the right slider in levels only to the left. The exposure slider can be moved in both directions.
The brightness slider does the exactly the same, except that it acts on the left bottom control in Levels. The contrast slider acts on both the right and left control.
In general, Levels is a much more powerfull tool [than the Exposure section] but can be trickier to use (and it is easy to spoil an image by making it look anatural). Its sliders can create much more drastic changes, e.g. extremely high contrast. And by offering midtone and quartertone controls, different tonal ranges can be adjusted differently. By moving the top sliders the these controls can be moved to any point in the tonal range.
When moving the right or left slider in Levels to the start of the histogram (to create pure blacks and whites), particularly when moving them quite a bit, one often might get better results by doing this separately for the three channels than on the luminance channel.
Generally, I have the impression that Exposure/Brightness/Contrast do a better job at balancing the three colour channels than the levels adjustment set to Luminance to maintain a natural look.
Comparing with the Curve tool (in e.g. Photoshop), one can state that levels and curves do exactly the same, the top controls on the diagram in levels in Aperture are the output of curves (y-axis) and and the bottom controls in Aperture are the input of curves (x-axis). The level controls in Aperture, however, 'only' have five control sliders at the bottom and only three at the top (and none at endpoints there).
An attempt to explain why all controls do more or less the same:
Take a B&W image (that makes things easier to understand). Any global image manipulation does nothing but remap luminence values. Every lumininence value in the original image gets translated into a value in the output, e.g., adding 20 (on the scale 0-255) to all brightens an image (probably not in a very smart way). This remapping is given by a functional relationship that can be illustrated by the curve in Curve tool. But there a lot of ways to represent that functional relationship, with levels being just another one (and one that I find more intuitive).

The exposure slider in Aperture does pretty much the same as moving the right bottom sliders in Levels. One difference is that one naturally can move the right slider in levels only to the left. The exposure slider can be moved in both directions.
The brightness slider does the exactly the same, except that it acts on the left bottom control in Levels. The contrast slider acts on both the right and left control.
In general, Levels is a much more powerfull tool [than the Exposure section] but can be trickier to use (and it is easy to spoil an image by making it look anatural). Its sliders can create much more drastic changes, e.g. extremely high contrast. And by offering midtone and quartertone controls, different tonal ranges can be adjusted differently. By moving the top sliders the these controls can be moved to any point in the tonal range.
When moving the right or left slider in Levels to the start of the histogram (to create pure blacks and whites), particularly when moving them quite a bit, one often might get better results by doing this separately for the three channels than on the luminance channel.
Generally, I have the impression that Exposure/Brightness/Contrast do a better job at balancing the three colour channels than the levels adjustment set to Luminance to maintain a natural look.
Comparing with the Curve tool (in e.g. Photoshop), one can state that levels and curves do exactly the same, the top controls on the diagram in levels in Aperture are the output of curves (y-axis) and and the bottom controls in Aperture are the input of curves (x-axis). The level controls in Aperture, however, 'only' have five control sliders at the bottom and only three at the top (and none at endpoints there).
An attempt to explain why all controls do more or less the same:
Take a B&W image (that makes things easier to understand). Any global image manipulation does nothing but remap luminence values. Every lumininence value in the original image gets translated into a value in the output, e.g., adding 20 (on the scale 0-255) to all brightens an image (probably not in a very smart way). This remapping is given by a functional relationship that can be illustrated by the curve in Curve tool. But there a lot of ways to represent that functional relationship, with levels being just another one (and one that I find more intuitive).

Levels vs Curves

What is the main difference betweem levles adjustments and curves?
Booth of these adjustment layers do the same in differnt ways:
contrast corrections, midtone correction, shadow/highlight corrections, color correction.
I understand curves allows to select secific tonal points in the image.
When should levels be used instead of curves?

Levels has the advantage that you can put the screen into Threashold mode by holding down the Alt/Opt key while dragging the end sliders. This is further enhanced in that you can see which channel, or group of channels, are at clipping by the colours you see on the screen.
Curves lets you target specific tonal range, or points, and also allows complex adjustments like when the curve has multiple high and low points. Levels can't do that. I also like the larger view of the histogram you can view with Curves.

Dunning Old dinning level and dunning level

Hi experts,
I have one issue in dunning. the issue is where the dunning history for particular customer shows as old dunning level as 3 and dunning level as 2.
i have checked the customer master there is change in the dunning procdure. But the document and master data shows the correct dunning level with the new procdure.
so i didnt understand what is the OLD dunning level and dunning level for the same cusomer. the issue is only with one customer.
I have also checked with old procdure with same customer in table MHNK. there are some notices done. but how come the current invoice shows the old dunning level for the same invoice.
can any once explain me how to proceed.
Regards
Ashok

Hi
Thnks for the reply so we need to apply this note for making the old dunning level and dunning level makes equal after you run the program.
Also one more doubt, since i have observed that the dunning after the parameters entered. looks like this
Parameters were maintained
Dunning selection executed, job deleted
Dunning notice printed, job deleted.
the above doesnt means that they will update the old dunning level right.
Regards
Ashok

Domain Level and Backup AD as VM?

We're currently running Windows 2012 R2 Essentials (25 users license default) as the DC. We're thinking to have the 2008R2 as the secondary (backup) DC. Questions are:
1. We have AD recycle bin enable, would it cause any issues lower the domain level to 2008R2?
2. Can 2008R2 run as a VM on a Hyper-V (the host is 2008R2 and part of the domain, but not DC)?
Thank you,

Yes you can run a VM and promote it as a Domain Controller, however if your domain / forest functional level is set to Windows Server 2012 then you cannot have a Windows Server 2008 R2 as a domain Controller. For this you need to have Windows Server 2008
R2 domain functional Level.
Domain Functional Level and Forest Functional level cannot be downgraded. if it's already set to Server 2012 functional level then you cannot downgrade it to 2008 R2. Please go ahead and check what's ur Forest & Domain functional Level
https://technet.microsoft.com/en-us/library/understanding-active-directory-functional-levels(v=ws.10).aspx
https://msdn.microsoft.com/en-us/library/cc753104.aspx
https://msdn.microsoft.com/en-us/library/cc730985.aspx
Nirmal Madhawa Thewarathanthri
Sorry but you are wrong. I just lowered the levels to 2008R2.

Levels and pre-fader metering

In the past I had always presumed the channel fader controlled the volume level of a softsynth. I know now that it obviously does not. It simply acts as a "faucet," so to speak. Meaning that increasing the fader level simply allows more of the synth's signal to pass.
So my question is this: Understanding that it is the instrument itself which is actually generating the signal (and consequetly the db's) should I keep all my faders at 0.00 on my audio instrument tracks and adjust the instrument levels instead when I mix? It would seem to make sense.
And in keeping with this method, as far as automation is concerned, would I be correct in assuming track volume should be automated via the instrument level?
I'm trying to keep all of this in the context of how it would be done in a studio with "real" instruments. Where the volume level is the volume level and if you want it louder you play harder or you turn up your amp. You want it softer you play your instrument softer.
I should add that this whole question/conundrum came up after I started recording with pre fader metering enabled and was quite surprised to see just how easy it is to clip a track (remembering of course that as long as no clipping is occuring at the master output I'm NOT actually clipping).

I don't know where all this "fader fear" is coming from.
In DSP terms, making something louder or quieter is simply a really simple DSP calculation. It doesn't matter whether you turn you softsynth down 3dB, or turn the fader down 3dB, the end result is exactly the same.
The faders are there for easy controlling of levels. It's why mixers were invented and designed this way.
I think these days someone reads a post on some esoteric audio forum about how their mix was so much better when they left the fader at 0dB in some obscure DAW back in the 90's, and translate that into "I must never use faders" or "I must never EQ" or "I must effectively work out my mix beforehand by my mic choice and positioning so all the signals magically combine into an artistic mix."
I'm trying to keep all of this in the context of how it would be done
in a studio with "real" instruments. Where the volume level is the
volume level and if you want it louder you play harder or you turn
up your amp.
You completely lost me here. Learning about gain staging is Elementary Audio Engineering Class 2 (the one afer the "what is a signal", and "what is a transducer").
You set the level of your recording device or mixer's input depending on the item you are recording, so the natural sound of whatever your source is corresponds to some nominal level for your recorder. It doesn't just magically happen on its own.
If you're recording an instrument that doesn't put out much sound level, you use the mic preamp to boost the signal to an appropriate recording level. And if you're recording Concorde taking off, you adjust your preamp, probably turning it down or padding the signal, again so it fits the range of your recorder.
Softsynths can put out a lot of level, and many preset designers don't pay much attention to volume levels in their patches. In addition, when you play a patch polyphonically, you're mixing together multiple signals (each of the notes you are playing) so you end up with higher levels still. It's good practice to pull down the output of the synth if it's too hot, but generally speaking, and avoiding getting into any "levels in Logic" complexities here, using the fader in Logic is exactly the same process.
Faders don't bite. Use 'em.

Current View as filter in BPC Vs Planning level and package in BPS

Hi,
     If I understand correctly, the current view is as like a filter in BPC as planning level and package in BPS, by comparing then I notice that the value for current can only be single value while in planning level and package we can have range, multiple value of single value.
    Let's have a planning scenario we need to planning for every month based on the actual month data,
in BPS we can easily configure two type of columns with actual and planning data, while in BPC, since the current view only allow single value, we have to copy the actual data to planning data, then with the category set to planning, we can do our planning. Of course if there is hierarchy, we can use parent to allow to display all the child.
   The other option is to use the EvGTS function which can retrieve the data outside the current view.
   Anybody have other though on this?
Edited by: JW on Jan 7, 2009 5:51 PM
Edited by: JW on Jan 7, 2009 6:25 PM

Hi JW-
I did not mean to imply that the Current View (CV) is not a filter. It can definitely be used to filter data presented from an EVDRE as well as other Ev functions, just like filters in BPS and IP. However as a developer you have the option to use the CV or, through your configuration, disregard and/or override the CV settings.
One example of disregarding CV settings is using standard Excel functions to provide the user a dropdown list from which to select certain dim members. The drop down box selection could be used instead of the CV for defining Ev function selections. My point is that you have multiple design paths of controlling what data is selected/processed; you are not only limited to the CV values. From a performance viewpoint, you are correct in assuming that limiting the data selection will greatly impact overall performance. Using the CV to limit data selection to enhance performance is very valid approach, just be aware that there are several alternative ways (other than using CV to control data selection) available to the developer.
-Sheldon

Ink level and cleaning facility

Had a new router fitted and could not reconnect printer to computer using HP website so used initial installation CD. Printer scans and prints ok.
However, the facility for detecting ink levels and carrying out ink jet cleaning etc are no longer present.
How can this be rectified please?

Hello there! Welcome to the forums @killick73
I understand you need the printers software installed on your Windows 7 system, after changing your router.
I am hoping this will help you!
Click this link, download and run the installation for the full feature software to have the software on your computer.
HP Deskjet Full Feature Software and Drivers
Check your desktop afterwards to see if the software works for you. If there are any troubles, please let me know the details.
Thank you, good luck!
R a i n b o w 7000I work on behalf of HP
Click the “Kudos Thumbs Up" at the bottom of this post to say
“Thanks” for helping!
Click “Accept as Solution” if you feel my post solved your issue, it will help others find the solution!

General differences - Bold and Curve

What are the basic differences and capabilities of all series of bold and curve? I've looked through their basic features, and obviously they each have blackberry standard applications. It looks like the curve may be more for multimedia and social. If so, what is the bold better for?
`violent rain

Hiya!
The main differences are in the hardware.
The curve is an entry level device wheras the Bold is a higher end (and more expensive) device
1). Please thank those who help you by clicking the beside the 'Reply' button.
2). If your issue has been solved, please resolve it by marking "Accept as Solution" on the correct post!
3). Remember to have fun! We are all in this together!
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CKMLCP - Level and Cycles Issue

Hello,
Could someone please help me to understand the multi-level logic specificaly about Level and Cycles ?
We have been in trouble trying to post MR22 in order to adjust some S-price but we can't find the right value to do it.
Is it the right way to adjust the S-price through MR22 respecting the level and cycle order ?
I've analysed CKMLP result and one of the interesting thing is that there are many materials without Cycle number. How do I do in this case ?
I'm appreciate for someone to help me.
Best Regards
Marcos

Hi Marcos
There are two ways to adjust price.
MR21: This is for standard price (S), but as you can have only one price per period, you only use if there is no previous movement for the material or if status is new/period open in CKM3.
MR22: This is for actual price, you can increase/decrease the actual costing for the material. It uses key UMB/BSX/PRD. When you post it will go for the material as price difference.
I hope I´ve helped you.
Regards

MCHB,MARD - Stock available at plant level and storage location level

Hi ,
How to determine how much stock available at Storage location level and Plant level. (Lot is not maintained).
In MCHB-Stock at lot level is shown.
In MARD-Stock at Storage Location level is shown lncluding
the stock maintaned at the lot level.
If i want to know the stock which is not maintained in Lot, i.e, Stocks directly maintained at Storage location / Plant.
Do I need to subtract the MCHB Value from MARD Value ?
Is there any other way available to find the stocks which is not maintained at lot level.
Regards
Prasath

Hi prashant,
What do u mean by stock maintained at SL level without batch level. Do u mean that some materials are subjected to batch management and some or not?
If that is the case, for all batch managed materials, u can see the stock at batch level and also same is summed up at SL level. But still what ever u are getting from MARD table isstock at SL level only.
If u have activated batch management for any material, it will always be shown at lot level also.
hope this clarfifies query
award points if found useful

How to improve the query performance in to report level and designer level

How to improve the query performance in to report level and designer level......?
Plz let me know the detail view......

first its all based on the design of the database, universe and the report.
at the universe Level, you have to check your Contexts very well to get the optimal performance of the universe and also your joins, keep your joins with key fields, will give you the best performance.
at the report level, try to make the reports dynamic as much as you can, (Parameters) and so on.
and when you create a paremeter try to get it match with the key fields in the database.
good luck
Amr

Table relationship between hierarchy level and merchandise category

1) Want to find Merchadise Category from Merchandise Hierarchy level which is attached with same Merchandise category.
I am having data/TABLE as below.
my input: M_WWG1C_class
i want to fetch data matkl in T023 or matkl in MARA for the same article within same merchandise category.
How i can have link?
2) i am having input CAWN_atwrt(Characteristic Value) and how i can reach matkl in T023 or matkl in MARA for the same article within same merchandise category.

Oracle does not support REPEATABLE READ transaction isolation level. It only supports SERIALIZABLE, READ COMMITED and READ ONLY isolation levels.
The default is READ COMMITED.
While the READ COMMITED can access all the committed data till the point of execution in transaction, READ SERIALIZABLE can access committed data till the point of start of transaction.
Another difference between two with respect to ROW LEVEL LOCKING is
Both read committed and serializable transactions use row-level locking, and both will wait if they try to change a row updated by an uncommitted concurrent transaction. The second transaction that tries to update a given row waits for the other transaction to commit or roll back and release its lock. If that other transaction rolls back, the waiting transaction, regardless of its isolation mode, can proceed to change the previously locked row as if the other transaction had not existed.
However, if the other blocking transaction commits and releases its locks, a read committed transaction proceeds with its intended update. A serializable transaction, however, fails with the error "Cannot serialize access", because the other transaction has committed a change that was made since the serializable transaction began.
Read following for clearing your concepts on transaction isolation levels and locking mechanisms
http://otn.oracle.com/docs/products/oracle9i/doc_library/release2/server.920/a96524/c21cnsis.htm#2414
Chandar

[svn] 3120: When you point Flex Builder at a local sandbox trunk build, it couldn' t generate the html-templates folder correctly for new projects so we moved all the html templates up one level and removed the html-templates directory and adjusted build

Revision: 3120
Author: [email protected]
Date: 2008-09-05 10:44:10 -0700 (Fri, 05 Sep 2008)
Log Message:
When you point Flex Builder at a local sandbox trunk build, it couldn't generate the html-templates folder correctly for new projects so we moved all the html templates up one level and removed the html-templates directory and adjusted build.xml's to accommodate the directory change
Modified Paths:
flex/sdk/trunk/build.xml
flex/sdk/trunk/webapps/webtier/build.xml
Added Paths:
flex/sdk/trunk/templates/client-side-detection/
flex/sdk/trunk/templates/client-side-detection/AC_OETags.js
flex/sdk/trunk/templates/client-side-detection/index.template.html
flex/sdk/trunk/templates/client-side-detection-with-history/
flex/sdk/trunk/templates/client-side-detection-with-history/AC_OETags.js
flex/sdk/trunk/templates/client-side-detection-with-history/history/
flex/sdk/trunk/templates/client-side-detection-with-history/history/history.css
flex/sdk/trunk/templates/client-side-detection-with-history/history/history.js
flex/sdk/trunk/templates/client-side-detection-with-history/history/historyFrame.html
flex/sdk/trunk/templates/client-side-detection-with-history/index.template.html
flex/sdk/trunk/templates/express-installation/
flex/sdk/trunk/templates/express-installation/AC_OETags.js
flex/sdk/trunk/templates/express-installation/index.template.html
flex/sdk/trunk/templates/express-installation/playerProductInstall.swf
flex/sdk/trunk/templates/express-installation-with-history/
flex/sdk/trunk/templates/express-installation-with-history/AC_OETags.js
flex/sdk/trunk/templates/express-installation-with-history/history/
flex/sdk/trunk/templates/express-installation-with-history/history/history.css
flex/sdk/trunk/templates/express-installation-with-history/history/history.js
flex/sdk/trunk/templates/express-installation-with-history/history/historyFrame.html
flex/sdk/trunk/templates/express-installation-with-history/index.template.html
flex/sdk/trunk/templates/express-installation-with-history/playerProductInstall.swf
flex/sdk/trunk/templates/metadata/
flex/sdk/trunk/templates/metadata/AC_OETags.js
flex/sdk/trunk/templates/metadata/readme.txt
flex/sdk/trunk/templates/no-player-detection/
flex/sdk/trunk/templates/no-player-detection/AC_OETags.js
flex/sdk/trunk/templates/no-player-detection/index.template.html
flex/sdk/trunk/templates/no-player-detection-with-history/
flex/sdk/trunk/templates/no-player-detection-with-history/AC_OETags.js
flex/sdk/trunk/templates/no-player-detection-with-history/history/
flex/sdk/trunk/templates/no-player-detection-with-history/history/history.css
flex/sdk/trunk/templates/no-player-detection-with-history/history/history.js
flex/sdk/trunk/templates/no-player-detection-with-history/history/historyFrame.html
flex/sdk/trunk/templates/no-player-detection-with-history/index.template.html
Removed Paths:
flex/sdk/trunk/templates/html-templates/

Remember that Arch Arm is a different distribution, but we try to bend the rules and provide limited support for them. This may or may not be unique to Arch Arm, so you might try asking on their forums as well.

Is there a way to change the color of the Bezier Curves and points to a different color other than black I find it perplexing while setting points and curves working on a photo that needs to be separated from it's background for placement on transparent

Is there a way to change the color of the Bezier Curves and points to a different color other than black I find it perplexing while setting points and curves working on a photo that needs to be separated from it's background for placement on transparent backgrounds. Any thoughts?

Yes. Well, sort of: instead of a "path", set the pen tool to "shape" in the tool properties. Then set the fill colour to transparent, and the stroke colour to the colour you want. You can also set the stroke width.
Not perfect, but at least you can see the path more clearly - the anchor points and handles still remain the default colour. Open the path panel, and right-mouse click the path shape to create a selection based on that shape. The Paths panel menu also allows you to create work paths based on that shape.
Unfortunately when you try to move the handles the black thin outline appears again until you release the mouse button.
This is one of several things that works better in Photoline: in Photoline, once the path is set to a specific colour, editing the path uses the actual colour and stroke width. which is extremely handy for creating path based selection with awkward background colours and/or a high resolution screen. In Photoline the handles and bezier points are also much, much larger, which makes it rather simpler to work with as well - especially on a higher resolution screen. And when selected the handles and points are a clear red with a black outline - again easier to spot and identify. I just works better, in my opinion.

Understanding Levels and Curves

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