ß This is a formative assessment instrument
ß You must be rated ‘Competent’ in this assessment item.
Learning Outcomes Learning Outcome 8 - Identify and explain a range of digital imaging concepts such as colour mode, colour space and bit depth as well as demonstrate typical fundamental digital image enhancement techniques, and identify digital image workflow patterns and create a simple file management methodology that conforms to established industry norms.
Tasks 1) Copy the file ‘Selections.jpg’ from eLearn and place it on the desktop. (Remember to delete this file when you have completed this exercise).
2) Start Photoshop and open the document ‘Selections.jpg’
3) Display the Histogram palette (‘Windows -> Histogram’)
4) Open the levels or curves palette (‘Image -> Adjustments ->Levels . . .’ and adjust the tonal range of the entire image, then close the palette. Observe the Histogram.
5) Select the rectangular Marquee tool – in the tool options bar set the feather value to 0, and the style to ‘Normal’.
a) Select a small rectangular portion of the image and observe the histogram.
b) Select a different area of the image and observe the histogram.
c) Click within the selected area and drag it to a new location.
d) What is the histogram showing you ?
It shows you the light spectrum range for that area
e) With the selection still active, open the levels or curves palette and make a change. What happens to the image ?
It changes the light spectrum range of that area
f) Use the selection types buttons to add to and remove areas from the selection .
g) Use the Shift and Alt keys to add to and remove areas from the selection.
h) Select ‘Select -> Inverse’. What happens to the selection ?
What is the shortcut key for this ? Shift command (I)
i) Select ‘Select -> Deselect’ or click once in the image to discard the selection.
What is the shortcut key for this ? command D
j) Use the History palette (‘Windows -> History’) to undo all the changes you have made.
k) Set the Rectangular Marquee style in the options bar to ‘Fixed Ratio’, enter a value for width and height (eg 2 and 3), then select an area of the image.
What do you observe ?
The ratio of the marquee remans the same eg 2 to 3 where as normal will be any size
l) Set the style to ‘Fixed Size’, enter a value for width and height (eg 200 and 100), then select an area of the image. NB You only need to click once – you don’t need to click and drag.
m) Set the ‘Feather’ value to 25, select an area of the image and make a tonal or colour change to the image. What do you observe ?
It fethers the edges so that the center of the selection is darkest and lighten to match the rest of the image
n) Press +D or click once in the image to discard the selection.
o) Use the History palette to undo all the changes you have made.
6) Select the circular Marquee tool – set the feather value to 0, and the style to ‘Normal’.
a) Select a small portion of the image.
b) Press +D or click once in the image to discard the selection.
c) Click and drag to start selecting a portion of the image. Before releasing the mouse button press and hold the shift key. What happens ?
Changes it from an elliptical shape to a perfect circle
d) Press +D or click once in the image to discard the selection.
e) Click and drag to start selecting a portion of the image. Before releasing the mouse button press and hold the Alt/Option key. What happens ?
It doubles the size of the selection
f) Press and hold the shift key while you select another portion of the image. What happens ?
It keeps the original circle and adds another
g) Press and hold the alt / option key and select a portion of the image that overlaps the existing selection. What happens ?
It minuses that small section
7) Select the Lassoo tool .
a) Select a small portion of the image.
b) Add and subtract areas to / from the selection and use the feather option.
c) Discard the selection
8) Select the Polygonal Lassoo tool .
a) Select part of the image by clicking a start point and adding nodes until you click on the start point again to finalise the selection.
b) Start a new selection and use the Esc key to abort the selection before you finalise it.
c) Start a new selection, add some nodes and then use the Delete / Backspace key to backstep through the nodes you have added.
d) Set the feather value to 2.
e) Select the two areas of the timber wall.
f) Use the Hue control to change the colour of the wall.
g) Go to ‘Select->Save Selection . . .’ and save the selection as Walls.
h) Discard the selection.
9) Select the Magnetic Lassoo tool .
a) Select the grey metal roof by clicking a start point and tracing along the edge to add nodes until you return to the start point to finalise the selection. Use the Esc key to abort, and the Delete key to remove unwanted nodes if you need to. Click on any point to force a node to be created. You may need to use the other selection tools to tidy up edges etc to make an accurate selection.
b) Save the selection as Roof.
10) Select the Magic Wand tool .
a) Set the tolerance to 32
b) Click in the sky to select part of the sky.
c) Hold down the shift key and click to add all the sky and clouds into the selection. Use +Z or the History palette to undo the last addition if required.
d) Save the selection as Sky
11) Use whichever tools you want to make and save a selection for the bricks.
12) Select ‘Select->Load Selection . . .’ and set Operation to ‘New Selection’ and reload the selection of the sky.
a) Use ‘Select->Inverse’ to invert the selection ie the entire building will be selected instead of the sky.
b) Save this selection as ‘Building’
13) Choose ‘Select->Color Range . . .’
a) Click on the blue part of the sky and use the Fuzziness slider to select all the blue sky.
b) Use the Burn tool to darken just the lower part of the blue sky without affecting the building or the white clouds.
c) You can use +H to hide the selection outline while you do this. Use +H to reveal the selection outline when you have finished.
14) Close the document.
15) Quit Photoshop.
16) Delete ‘Selections.jpg’ from the desktop.
17) Shutdown the computer.
