Tuesday, 13 September 2011

Non-Destructive Image Editing - 3



Part III – Catalogue-Based Non-Destructive Imaging
  1. What model does cataloguing software use ?
           The model that is used in the library model.

  1. Where are the images stored in a catalogue based system ?
         In a folder, multiple folders, USB, internal/external drive or        CD/DVD.


  1. Where does the catalogue get its initial information about the files ?
            Metadata

  1. Where does the cataloguing software store this information ?
           The Catalogue
  1. What is the main organising principle of Browser based systems ? The file system
  2. How do cataloguing systems organise their images ?
A cataloguing system runs on metadata.
  1. How does a cataloguing system make changes to an image ?
           It updates the metadata.        
  1. Can other programs see these changes ?                               No
  2. How does a cataloguing system make changes to an image available to other programs ?
          You need to export the file.     

     10.List 5 advantages of Cataloguing based PIE software ?
    1. It doesn't change the original data of the image. Totally non-destructive.
    2. Can bring images together from all over the place, all accessed through a central database.                                                                                                                                                
    3. Edits can be applied to several images.                                                                                                                                                
    4. Backing up and restoring becomes easy.                                                                                                                                                
    5. Exporting.
  1. Give two examples of software that combine Image Cataloguing and Editing functions ?
    1. Lightroom.
    2. Capture.

Tuesday, 6 September 2011

Non-Destructive Image Editing

Operation
ND / D
Comments / ND Alternative


Levels / Curves
Yes/yes
In order to do this non-destructively, you should use an adjustment layer.


Rotate Image
yes/ yes
This is only non-destructive depending on the angle you rotate your image at.


Clone Stamp
yes/yes
Non-destructive if you do it on a separate layer.


Save file from ACR
yes/yes



Dodge / Burn
yes/yes
adjustment layer and layer mask.


Merge Layers / Flatten Image
destructive



Paint Brush
yes/yes
adjustment layer and layer mask


Flip Layer
non-destructive



Cut part of image out from background
yes/yes
layer mask


Erase Tool / Delete Selected Pixels
yes/yes
layer mask


Transform Selection – rotate, skew, etc
yes/yes
smart object


Flip Selection
yes/yes
depending on the image, you may be able to copy the selection to a new layer and then flip it. 


Convert to B/W
yes/yes
adjustment layer using hue and saturation


Apply a Filter
yes/yes
smart object


Change Layer Opacity
non-destructive



Change Bit Depth of Image
yes/yes
depending on weather you are adding bits from 8 to 16 bits or reducing the bits from 16 to 8 bits. 


Resize Image
yes/yes
nob-destructive if using smart object.


Apply a Layer Style
non-destructive



Crop Image
yes/yes
use smart object


Add an Adjustment Layer
non-destructive



Sharpen the Image
yes/yes
use smart object


Apply Lens Correction
yes/yes
use smart object



Non-Destructive Image Editing - 2

Part II – The Rendering Engine
What is a Rendering Engine ?
The rendering engine refers to the software that takes all the information...the image and the instructions and generates the final image.
What three things determine the final colour of an image pixel ?
Mathematical formulas of the rendering engine, original image file (jpeg, tiff, dng, pdf, psd, png) , user settings.

What are the three main components of a RAW file ?
Metadata, the Mosaic (raw data), jpeg preview (internal rendering engine of camera generates this),  

Can PIE software be used only on Raw files ?  No
What is a Live Rendering ?
A live rendering is a view of the image that only exists when the source image is loaded into the software. The software grabs the source information and generates a preview of the image. A fixed rendering is when we take the preview and save it as a file, or print the image.

Where can the Rendering Metadata be stored ?
Saved inside the image file, in the database or catalogue, or the sidecar file xmp (extencible metadata platform).

When saving the metadata inside the image file, it can only be done in certain file types as it may corrupt the file. You cannot safe metadata inside a raw file.
A sidecar file allows you to attach metadata to a file on the side. A problem with sidecars is that they may get separated from your image file and you could loose the editing that you have added to an image.
Using Lightroom with a catalogue is the best way to go.


Give two examples of a Fixed Rendering
a. Saving a file as a jpeg, tiff,etc. This locks in the information. b. Printing the image.
Is a Preview a Live or a Fixed Rendering of the image ?
Live rendering.

Tuesday, 30 August 2011

Non-Destructive Image Editing

Questions
Part I – The Evolution of Non-Destructive Imaging
  1. Define ‘Non Destructive Imaging’
This refers to imaging processes where the source image may be adjusted in a way that leaves the original data intact.
  1. List four challenges introduced by digital photography :-

    1.  The creation of a vast number of photos.

    1.  The need to apply identical adjustments to many photos in one operation.

    1.  The need to interpret a single source image in multiple ways (black and white, and colour, for instance).
    2. The desire to take advantage of rapidly evolving imaging technology to reinterpret images with more capable software in the future.
  1. What is meant by a ‘Derivative File’ ?
This refers to a version of the photo file that has had some adjustments incorporated—which is called a derivative file, since it’s derived from the original.
  1. What are two problems with using ‘Save As …’ to create derivative files ?
    1. The creation of multiple variations of a photo could bring great confusion
    2. The entire file needs to be resaved, even small changes require resources to duplicate and archive the entire file which takes up a lot of storage space.
  2. What is ‘Self Referenced Non Destructive Imaging’ ?
Refers to when adjustment layers were introduced, and it became possible to wrap up the source image with a set of instructions (or many sets of instructions) for rendering the photo. An adjustment layer is the instruction that tells the software how to manipulate the image and applies these instructions to the image. This is information that is saved as metadata, and doesn't change the source file.
Source File + Instructions = Final Appearance.

  1. List two advantages of Self Referenced NDI over the use of Derivative Files :-
    1. Much more economical in terms of storage.
    2. Is much easier to sort out what has been done to an image



  2. Define ‘Parametric Image Editing’ :
Refers to the editing of images by creating instructions or parameters.

  1. What is the difference between a Live Rendering and a Fixed Rendering ?
A live rendering is a view of the image that only exists when the source image is loaded into the software, whereas fixed rendering refers to any image that has its rendering described in pixel information, such as an RGB or a grayscale value, we can view this as a jpeg, where all edits have been locked in and can no longer be undone. 
  1. List three advantages of NDI :
a.        Saves money                                                                                                         
b.        Saves Time                                                                                                            
                        c.        Allows Creative freedom                                                                                         

Presintation Tutorial - Airbrushing

The Tutorial that I completed and decided to do my presintation on was Airbrushing.
In this tutorial, I learnt how to airbrush skin whilst keeping a natural looking texture, so that it doesnt look too fake.

Here are the before and after images of my tutorial:

                                       BEFORE                                                     AFTER

The instructions to this tutorial by 'Admin' can be found on:

Excercise 4 - Colour Theory 2

Tasks
1.       Start Photoshop and open the document you created in Exercise 3.
·         What is the keyboard shortcut for opening an existing Document ? - Ctrl + O
2.       Change the Blending Mode of the layer Group to ‘Pass Through’.
3.       Make the background layer the working layer by selecting it in the Layers palette.
4.       Use the Rectangular Marquee tool to select the top half of the image.
5.       Use the Paint bucket tool to fill this area with Black.
·         What is the keyboard shortcut for this tool ? - G
6.       Change the Blending Mode of the ‘Red Circle’ layer to ‘Lighten’.
7.       Do the same for the Blue and Green Circle layers.
8.       Select the Move tool.
·         What is the keyboard shortcut for this tool ? - V
9.       Turn on the ‘Auto-select’ option and set it to ‘Layer’ (Not ‘Group’).
10.   Drag the three circles so they all overlap each other.
11.   This simulates the Additive Colour System.
12.   Rename the group of circle layers to indicate this.
13.   Add a text layer (using white text) saying ‘<name> Colour System’.
14.   Select the group of circles in the layers palette.
15.   Duplicate the group using ‘Layer -> Duplicate Group …’.
16.   Use the Move tool with ‘Auto-Select’ set to ‘Group’ to drag the new group to the bottom half of the page.
17.   Change the Blending Mode of the this group to ‘Difference’.
18.   This simulates the Subtractive Colour System.
19.   Add a text layer saying ‘<name> Colour System’.
20.   Save the document as ‘Ex 4 – Primary_Colours.psd’


                  Additive and Subtractive Colour systems