What is digital imaging

Wikipedia says that

Digital imaging or digital image acquisition is the creation of photographic images, such as of a physical scene or of the interior structure of an object. The term is often assumed to imply or include the processing, compression, storage, printing, and display of such images.

The ECDL Foundation, who prescribe the European Computer Driving Licence curriculum, have used the phrase image-editing to mean working with images using image editing software (eg Photoshop).   Their curriculum (see my notes on it) doesn't include creating or capturing digital images, presumably because this is regarded as photography. 

Some local institutions which teach this image-editing curriculum use Digital Imaging as the title of their courses.

As the lines between computers and cameras has blurred (to the point where all cameras are now computers, and most computers and mobile phones include a camera), the distinction between image capture and image editing has become less useful.

The working definition in this blog is that Digital Imaging is working with digital images in any way:

• creating them, 
• editing or manipulating them, 
• outputting (on any medium - via a printer, plotter, screen)
• managing them  (storing, filing / cataloging, sharing, archiving, deleting).

ECDL syllabus and these notes WIP

Links between the ECDL Digital Imaging syllabus and my notes about each item on it when Photoshop is the application being used.

1 Imaging Concepts

1.1 Digital Images

1.1.1 Identify common uses of digital images
Web and print publishing, distribution by e-mail and mobile phone, home printing, digital photo frames.

1.1.2 Understand the terms pixel, resolution and identify the key features of a digital image: composed of discrete pixels, represented digitally in binary code.
My notes:  Basic imaging concepts

1.1.3 Understand the terms lossy, lossless image file compression.
My notes:   some common imaging formats

1.1.4 Understand the term copyright and the implications for image use. Understand the terms royalty-free images and rights-managed images.
My notes:   copyright, digital images and rights management

1.2 Graphic Formats

1.2.1 Understand the terms raster and vector graphics and distinguish between them. Identify common raster (jpeg, gif) and vector (svg, eps) formats.
My notes:   Types of graphics - raster vs vector

1.2.2 Recognize proprietary digital image editing application formats: psd, psp, xcf, cpt.
My notes:   some common imaging formats

1.3 Colour concepts

1.3.1 Understand the term colour model and recognize common colour models: RGB, HSB, CMYK, grayscale.
My notes:  colour concepts

1.3.2 Understand the terms colour palette, colour depth.
My notes:  colour concepts

1.3.3 Understand the terms hue, saturation, colour balance.
My notes:  colour concepts

1.3.4 Understand the terms contrast, brightness, gamma.
My notes:  colour concepts

1.3.5 Understand the term transparency.
My notes:  colour concepts

2 Image Capture

2.1 Capturing Images

2.1.1 Save an image from a digital camera to a location on a drive.
My notes:  saving an image from a digital camera to your computer

2.1.2 Use the print screen facility to capture a full screen, active window.
My notes:  using the PrintScreen function in Windows

2.1.3 Save an image from an image library, web page to a location on a drive.
My notes:  Image capture - saving a web-page to your computer

2.1.4 Open a scanning application and scan an image: preview, set scanning parameters, scan, save.
My notes:  Image capture - scanning a document

3 Using the Application

3.1 Image Creation

3.1.1 Open, close an image editing application. Open, close image files.
3.1.2 Create a new image file and set options: colour model, size, resolution, background colour.
3.1.3 Create a new image file from clipboard.
3.1.4 Switch between open image files.
3.1.5 Save an image to a location on a drive. Save an image under another name to a location on a drive.
3.1.6 Save, export an image as another file type like: jpeg, gif, tiff, png.

3.2 Settings 

3.2.1 Set background colour, foreground colour.
3.2.2 Set grid properties: units, horizontal spacing, vertical spacing, colour.

3.3 Enhancing Productivity

3.3.1 Set basic options/ preferences in the application like: transparency, grid settings, measurement units.

3.3.2 Use available Help functions.

3.3.3 Use magnification/zoom tools.

3.3.4 Use the undo, redo command. Use the undo history.

3.3.5 Display, hide built-in toolbars, palettes, windows.

4 Working with Images

4.1 Selection

4.1.1 Select an entire image, layer(s).
4.1.2 Set selection tool properties: relationship between multiple selections, feathering, antialiasing, width, height.
4.1.3 Select part of an image using selection tools: rectangular, elliptic, magic wand, magnetic lasso, freehand image.
4.1.4 Inverse a selection.
4.1.5 Save a selection, load a saved selection.
My notes:   Basic image actions

4.2 Image Manipulations

4.2.1 Change the canvas size of an image.

4.2.2 Resize an image in pixels, measurement units.

4.2.3 Crop an image.

4.2.4 Copy, move image(s), selection within an image.

4.2.5 Rotate, mirror an image, selection within an image.

4.3 Layers 

4.3.1 Define and understand the term layer.
4.3.2 Create, copy, delete a layer.
4.3.3 Set layer properties: name, hide, show, lock, opacity, blending mode.
4.3.4 Arrange, merge, link, flatten layers.
4.3.5 Transform layer(s): scale, rotate, flip, move, trim.
4.3.6 Convert a drawn object to a raster layer.
My notes:   Working with layers in Photoshop

4.3.7 Create an animated gif from layers.
My notes: 

• How to create an animated GIF using Photoshop
• How to make animated GIF using GIMP  (link to external article)

4.4 Text

4.4.1 Add, edit, delete text.
4.4.2 Copy, move text.
4.4.3 Align text: left, centre, right, justified.
4.4.4 Apply text formatting: font sizes, font types, font colour.
4.4.5 Apply a text warp.
My notes:   Working with text in Photoshop

4.5 Effects and Filters 

4.5.1 Apply artistic, distortion effects: pixelate, emboss, wind, ripple, twirl, desaturate.
4.5.2 Apply blur effects: gaussian, motion.
4.5.3 Apply lighting effects: lighting, flare.
4.5.4 Apply adjustments: brightness, contrast, hue-saturation, colour balance.
4.5.5 Apply sharpen, unsharpen mask.
4.5.6 Apply red eye reduction. 

My notes:

• Effects vs Filters in Photoshop
• Adjusting images in Photoshop (filters etc)
• Red eye recuction in Photoshop

5 Drawing and Painting

5.1 Drawing Tools 

5.1.1 Add a line to an image: straight line, free drawn line, curves. Set, modify line weight, style and colour.

5.1.2 Add a shape to an image: rectangle, ellipse, n-shaped polygon. Set, modify line, fill style and colour.

5.2 Painting Tools

5.2.1 Pick up a colour value with the dropper.

5.2.2 Fill a portion of an image with the gradient tool, selecting opacity/transparency, radial, linear, position, rotation.

5.2.3 Colour a portion of an image with the paintbrush tool, selecting colour, shape, size.

5.2.4 Erase a portion of an image with the eraser tool, selecting its shape and size.

5.2.5 Fill a portion of an image with colour using the paint bucket tool.

5.2.6 Clone a portion of an image using a clone tool, selecting size, opacity.

6 Prepare Outputs

6.1 Setup

6.1.1 Preview an image.
6.1.2 Select appropriate colour depth, resolution, image size, graphic format for web, screen, print use.

6.2 Print 

6.2.1 Change print output orientation: portrait, landscape. Change paper size.
6.2.2 Print an image to an installed printer using defined options, default settings.

My notes for this whole section:   Preparing image output from Photoshop

Photoshop - basic image actions

Before doing any action in Phtotshop, you need to select the correct layer to work on.

How to select a layer

1. Use the Select drop down menu and choose all layer OR

2. Click on them in the layers tab.



Once you have selected a layer, you need to choose which part of the image on that layer to work on

How to select a whole image

• Use a selection tool: Click once to select; click again to deselect  OR
• Use a keyboard shortcut: the fastest whole-image selection, is Ctrl+A (Windows) or command+A (Mac).  OR
•  Use menu command: Selection > Select All (or similar - may chancge between versions)

Note: other useful items on the Selection menu: Select None or Deselect (Ctrl/d) that turns off an existing selection.

Use one of these tools to select part of an image:

• Lasso
• Polygonal Lasso
• Magnetic Lasso
• Elliptical Marquee
• Magic Wand
• (and more?)

Note that once you have selected the tool, you can see its options bar - tools have different options.

Properties of the Selection tools 

The Lasso, Polygonal Lasso, Magnetic Lasso tools are hidden in the Toolbox under one and the same icon. The icon on the Toolbox displays the last selected tool. Use the floating menu to choose one of these others. To access it, right-click on the arrow in the lower right corner of the displayed icon.

The Lasso tool 

This is useful for drawing freeform segments of a selection Select the Lasso tool, and set feathering and anti-aliasing in the options bar. (See Soften the edges of selections.), and then use the mouse to draw the border of the area.

The options bar has selectors for a new selection, or

• add to,
• subtract from,
• intersect with

the existing selection.


With the Lasso tool, you can:

• Drag to draw a freehand selection border.
• Switch between freehand and straight-edged selection by pressing Alt (Windows) or Option (Mac).
• Click where segments should begin and end.
• Erase recently-drawn straight segments by pressing the Delete key.
• Close the selection border by releasing the mouse without holding down Alt (Windows) or Option (Mac).
• Optional - Click Refine Edge to adjust the selection boundary.

To use the Lasso tool

• Select the tool
• Click at the first point of the area to be selected using the left button
• Left-click at points around the area, to outline it.

The Rectangular marquee tool

This is used to select rectangular and square areas.

• Activate it by clicking on the icon or select it from the floating window.
• Put the mouse cursor where the corner of an imaginary rectangular should be, and press the left button.
• Keeping the left button pressed, move the cursor to the diagonally-opposite corner
• Release the button.

To select a square area keep the SHIFT key pressed while selecting. But remember that this will also add the new selection to any existing selection.

The Elliptical marquee tool 

This is used to select ellipses and circles.

• Select the Elliptical marquee tool from the Toolbox by clicking on the icon or select it from the floating window.
• Put the cursor at the point where the corner of an imaginary rectangular with an inscribed ellipse should be
• Press the left button.
• Keeping the left button pressed, move the cursor to the diagonally-opposite corner
• Release the button.

Select a circular area by keeping the SHIFT key pressed. But remember that this will also add the new selection to any existing selection.

Alternative: hold the Alt (Windows) or Option (Mac) key while when selecting an elliptical or a rectangular area, and the selection is made from the center to borders, instead of corner to corner.

The Polygonal Lasso 

This is also used to make freehand selections, but the contour of the selections is made up of straight segments. To use it:

• Select the Polygonal Lasso tool
• Put the cursor on any point that is to be part of the outline,
• Click the left mouse button, to mark the first point of the contour.
• Move the cursor an adjoining point of the contour and left-click it: a straight-line selection will be made between the two points.
• Repeat the previous step until the 2nd-to-last point is made.
• Click on the first point (which is also the last point) again to close the contour.

The Magnetic Lasso 
This is also used to make a freehand selection, but you don't have to follow the contour of the object precisely: any object that stands out against the background of the selected area is traced automatically when you move the cursor along the object. To use it:

• Select the Magnetic Lasso tool
• Put the cursor on any point on the edge of the object to be selected
• Hold down the left button and start dragging the cursor along the object. Fastening points will appear as you outline the object and when you make a click. If a one is irrelevant, remove it by pressing the DELETE key and return to the previous fastening point to continue outlining the object.
• Close the contour by joining the first fastening point to the last one by bringing the cursor to the first point or by making a double-click.

The Magic Wand tool 

This elects a consistently coloured area.  The options bar has a place to set the Tolerance - for this, the higher the tolerance, the more colours will be selected with a single click. Valid values are 0 to 255:  0 means only one colour is selected, 2255 means all colours in the image will be selected.

To use it:
1. Select the magic wand tool.
2. Move the cursor to a pixel which must be in the selection and left-click. 
When you do this, an outline ("marching ants") appears around the pixel, and all other pixels in image with a similar colour, within the specified Tolerance value.

These selection tools are efficient due to the flexibility of their usage: you can add to, subtract from or intersect a selection.

• Add by holding the SHIFT key.
• subtract by holding the Alt (Option in Macintosh) key 
• Intersect by holding the SHIFT and Alt (Shift and Option in Macintosh) keys 

 while selecting more pixels with the "same" colour.

Invert a selection

Inverting a selection swaps the currenly selected and unselected areas  (so currently unselected becomes selected)

Use it from the menus, by choosing Select > Inverse.

Hint:  this is the easiest way to select an object which is set against a solid-colored area:  just select the solid colour with the Magic Wand tool, and the use Select > Inverse.

Softening the edges of a selection

There are two techniques for this.

Anti-aliasing smooths the jagged edges of a selection by softening the colour transition between edge pixels and background pixels. Only the edge pixels change, so no detail is lost. This technique is useful when cutting, copying, and pasting selections to create composite images.

Anti-aliasing is available for these tools:
Lasso
Polygonal Lasso
Magnetic Lasso
Elliptical Marquee
Magic Wand


You need to specify anti-aliasing before using the selection tool -  you cannot add it after selection.   Therefore to use it:

1. Select the tool.
2. Select Anti-aliased in the options bar.
3. Select the area to be anti-aliased.

Feathering blurs edges by building a transition boundary between the selection and the surrounding pixels. This may cause some loss of detail at the edge of the selection. 

Feathering is available for these tools:

• Marquee
• Lasso
• Polygonal Lasso
• Magnetic Lasso tool

Feathering effects only show after you move, cut, copy, or fill a selection.   So to use feathering

1. Select a tool.
2. Enter a Feather value in the options bar. (from 0 to 250 pixels)
3. Select the area to be feathered
4. CHECK - IS THIS WHERE YOU NEED TO CUT/COPY AND THEN PASTE?

To define a feathered edge for an existing selection
1. Choose Select > Modify > Feather.
2. Enter a value for the Feather Radius, and click OK.

Issues with feathering:
A small selection made with a large feather radius may be so faint that its edges are invisible and therefore not selectable. If you see the message “No pixels are more than 50% selected,” either decrease the feather radius or increase the size of the selection. Or click OK to accept the mask at its current setting and create a selection in which you cannot see the edges.

Facts for marketing about cryptocurrency

Cryptocurrency is “digital money” (a means of payment) that isn't controlled by any single entity (eg a bank or a government). This gives people and organisations using it more anonymity than normal online payments, the payment experience is simple, with few / no fees or middleman.

Bitcoin was the first cryptocurrency (created in 2009), there are now 1,000+ of them, all tryng to get market share. Eg Dash, Litecoin, Ethereum, Monero.

Most cryptocurrencies work using blockchain technology: essentially an encrypted ledger of transactions simultaneously kept and updated by a very large number of peer-to-peer computers in a decentralized network, based on a set of cryptographic rules.

Not relying on a single certification authority, means that blockchain can be sure that every cryptocurrency unit can only be spent once and transactions can't be forged.

One way to create cryptocurrency units is mining: people use powerful computers to solve complex cryptographic puzzles (complex mathematical equations).
Blockchain is important beause the underlying concept has potential for many more valuable business uses. No one can change data stored in a blockchain so it's always a “single source of truth”
Possible applications of blockchain are many and it's currently in the very early stages.

Some possible ways that blockchain will affect business:

• Frictionless transactions – faster and easier buying experience, with less fees and delays. Sellers get immediate cash flow, full transaction value (no fees to a middleman), and no the possibility of chargebacks and fraudulent credit card transactions. 
• Greater customer privacy – cryptocurrency transactions don't have to reveal the customer’s identity. So Marketing might not automatically get the data they get today.
• Fewer data breaches – with cryptocurrency transactions, seller deosn't store any personal payment details that could be stolen in a data breach. 
• Micropayments – consumers paying small amounts for things like consuming content - so publishers and vendors could earn revenues, without using ads. Cryptocurrencies may finally make micropayments viable (maybe). 

Why to consider accepting cryptocurrencies now:

• To attract customers who prefer to pay using cryptocurrencies such for privacy or who are attracted to more tech-savvy businesses. 
• To get experience with this new payment method. 
• Media coverage if it's new in your industry

Risks and issues
Volatility in the value of cryptocurrencies, due to no government backing
Limted circulation, newness, high-risk investment vehicle
Some major companies accept Bitcoin now (eg Microsoft, Amazon, Apple App Store, Home Depot, Victoria’s Secret, Dell, Expedia) but they are large enough to take the volatility risks
Volatility may or may not disappear with maturity,

Brush tool details

Photoshop's Brush tool draws lines and shapes, using strokes.

At their most basic, brushes let you achieve the same effect as physical media like paint or colouring pens. But they can be used other things, eg textures, patterns and lighting too.

As well as the standard brushes that come with Photoshop, designers can create others and release them as .ABR (a-brush?) files.

Installing brushes

If you get 3rd party .abr files, you can install them by

• Dragging and dropping them into Photoshop (for versions that support this)
• From the menu, choose, Edit > Presets > Preset Manager. Then select Brushes from the dropdown, and use the Load button to add them.

Configuring brushes

Once a brush is selected, there are settings:

• In the top toolbar for the type of brush, size, mode, opacity, and flow of the brush.
• In the brush panel (menu Window > Brush) - options for shape dynamics, scattering, texture, dual brush, colour dynamics, transfer, noise, wet-edge, airbrush, smoothing, protect-texture.

Using brushes

Single click for a single brush stroke, or hold the mouse button and drag the cursor around to create effects.

How to use filters to sharpen something in Photoshop

Use Filter > Sharpen > Unsharp mask     

Effects (fx) vs Filters

An effect is applied to a selected item   (eg text, shape).

A filter is applied to a whole image.