This is the step by step workshop for image editing basics session. This was run at the CNAQ in Doha, Qatar for college staff.

1. John Allan 2016
Image Editing 1 - Learn the basics of Image Editing
Topics addressed in this workshop include:
• resizing
• selection tools
• rotation
• cropping
• distortion
• colour adjustments
We will be using the PIXLr Editor resource
Preparation:
• Sign in to your workstation
• Load the folder Image_workshop_images onto your desktop
Workshop
Resizing – to fit in media and reduce storage size
1. Surf to http://apps.pixlr.com/editor/
2. A Pop up appears
3. Choose Open the image from computer
4. Locate the folder Image_workshop_images
5. Click on the file CitySkyline.jpg
6. Click on the Open button
7. In the Menu bar, click Image, Click Image size…
8. The dimensions of the image appear in the Image size pop up
9. Click OK

2. John Allan 2016
10.To determine the current storage size of the image, click File, clickSave
11.Note: With Jpeg files (most photographs are saved with this format)
The higher the quality setting, the more file storage required. Normally
the Quality setting for web based images is between 80 and 100
12.It is your job to find a balance between aesthetic value vs file size.
13.Jot the file size down on a piece of paper.
14.Click Cancel
15.On the menu bar, click Image
16.Click Image size…
17.Ensure that the Constrain proportions check box is ticked
18.Change the Width to 400 pixels
19.Note that the Height setting is automatically changed to 300 Pixels
20.Click on the OK button
21.On the menu bar, click View
22.Click Actual Pixels
23.To determine the current storage size of the image, click File, clickSave
24.Note the difference. It is quite substantial.
25.In the Name field change the name to CitySkyline_small
26.Click OK
27.Select a suitable location then click Save
28.Close the file

3. John Allan 2016
Rotating – correct images with odd orientation
1. Choose Open the image from computer
2. Locate the folder Image_workshop_images Click on the file
Wind_mill.jpg
3. Click on the Open button
4. In the Menu bar, click Image
5. Click Rotate canvas 90 CW
6. Click File, click Save
7. Click OK
8. Select a suitable location then click Save
9. Close the file

4. John Allan 2016
Selection Tools – choosing what to change
The section tools are: crop (see next section), marquee,
lasso, wand
Marquee
1. Choose Open Image From Computer
2. Locate the folder Image_workshop_images
3. Click on the file tower.jpg
4. Click Open
5. On the toolbar (on the left) choose the Marquee tool
6. Click and drag to select a rectangular section of the clock tower
At this point we will change the selected portion of the
image using a predetermined feature or “filter”
7. On the Menu bar, choose Filter then click Hope
8. On the Menu bar, Click Edit, Deselect All
9. Click File, click Save
10. Click OK
11. Select a suitable location then
click Save
12. Close the file
Note: The marquee
tool can also select
circles if the modifier
ellipsis is selected

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Lasso
1. Choose Open Image From Computer
2. Locate the folder Image_workshop_images
3. Click on the file rubber_duck.jpg
4. Click Open
5. On the toolbar (on the left) choose the Lasso tool
6. Click and drag to trace a selection path
around the duck
At this point we will invert the section to include
the background then change the background
using a predetermined feature or “filter”
7. On the Menu bar, click Edit, Invert selection
8. On the Menu bar, choose Filter then click Kaleidoscope
9. Click Ok
10.On the Menu bar, Click Edit, Deselect All
11.Click File, click Save
12.Click OK
13. Select a suitable location then click Save
14.Close the file
Note: The lasso tool can also select with angles and straight lines if the modifier
polygonal is selected

6. John Allan 2016
Wand (magic wand)
1. Choose Open Image From Computer
2. Locate the folder Image_workshop_images
3. Click on the file villa.jpg
4. Click Open
5. On the toolbar (on the left) choose the Wand tool
6. On the modifier tool bar, set Tolerance to
40 pixels
7. Click on the sky in the image
At this point we will remove the sky then change the background to a night sky
8. Press the Delete key, the sky should turn white
9. At the bottom of the Toolbar, ensure the Main color chip is black
10.On the Toolbar, choose the Paint bucket tool
11.Click in the selected area (the sky)
12.On the Menu bar, Click Edit, Deselect All
13.Click File, click Save
14.Click OK
15.Select a suitable location then click Save
16.Close the file

7. John Allan 2016
Cropping Tool
1. Choose File, Open Image From computer
2. Locate the folder Image_workshop_images
3. Click on the file Moon.jpg
4. Click Open
5. On the Tool bar click crop
6. Drag the mouse pointer around the moon so reduce the
black background
7. The crop bounding box appears
8. Press the Enter key
9. The result is a more dominant moon.
10.Click File on the Menu bar
11.Click Close
12.Click No

8. John Allan 2016
Distort
1. Choose File, Open Image From Computer
2. Locate the folder Image_workshop_images
3. Click on the file jump.jpg
4. Click Open
5. On the Menu bar, click Edit
6. Select Free distort…
7. Drag the corner nodes inwards
8. When satisfied with the result, press the Enter key
9. Click File on the Menu bar
10.Click Close
11.Click No

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Colour adjustment
1. Choose File, Open Image From Editor
2. Locate the folder Image_workshop_images
3. Click on the file two_cats_before.jpg
4. Click Open
5. On the Menu bar, click Adjustment
6. Click Auto levels
Note: If this always happened the other adjustment tools would not
be necessary
7. On the Menu bar, click Adjustment
8. Click Brightness and Contrast
9. A pop up appears
10.Slide the Brightness setting to 50
11.Slide the Brightness setting to -50
12. Return the Brightness setting to 0
13.Slide the Contrast setting to 100
14.Slide the Contrast setting to -70
15. Return the Contrast setting to 0
16. Click Cancel
17.On the Menu bar, click Adjustment
18.There are 16 features in the Adjustments menu explore a few.
Note that the changes are additive.
19.When you are finished, close the file.
* All images Free Copyright from MorgueFile.com

10. John Allan 2016
Challenge activity
Use the skills /tools learned to change this image to the image below.
1. Choose File, Open Image From Computer
2. Locate the folder Image_workshop_images
3. Click on the file Pixlr_challenge.jpg