Skills: rotate, select, crop, resize, change contrast, filter, compressConcepts: image processing operation, information

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An image processing session

Where does this topic fit?

• Internet concepts– Applications– Technology– Implications

• Internet skills– Application development– Content creation (image)– User skills

Selected image processing operations

• Rotate an image • Crop an image• Change image contrast• Apply a filter to an image• Resize an image• Select a portion of an image

Start with a picture of Lucas

2,048 by 1,536 pixels (zoom out to fit laptop screen)

Operation: rotate

Operation: crop

357 by 381 pixel image (shown full size)

Operation: adjust contrast

Operation: apply the “ink sketch” filter

Operation: resize

200 by 213 pixels

Operation: crop

200 by 200 pixels

Tool option and status areas

15.3 kilobytes40.2 kilobytes

Operation: compress

Image processing work flow

Capture

Edit

Compress

Distribute

Try this for yourself

The original picture of Lucas is at:

http://som.csudh.edu/fac/lpress/netApps/image/lucasoriginal.jpg

Zooming versus resizing

2,048 by 1,536 pixels (3 megapixels)

1,920 by 1,200 pixels

Summary

Resources

Tutorials:http://www.getpaint.net/doc/latest/index.html

Download, forums, blog and email contact:http://www.getpaint.net/doc/latest/WebLinks.html

1. We illustrated several image processing operations in this presentation. Without looking back, do you recall what they were?

2. Can you describe what each does to an image?3. Can you think of any other image processing operations that we did not use in

this presentation?4. If one zooms in on an image is information lost or gained?5. If one resizes an image, making it smaller, is information lost?6. If one resizes an image, making it larger, is information gained?7. If one crops an image, is information lost?8. If one filters an image, is information lost?9. If one compresses an image, is information lost?10. If one zooms in on an image, which of its characteristics are changed?11. If one resizes an image, which of its characteristics are changed?12. If one crops and image, which of its characteristics are changed?13. If one filters an image, which of its characteristics are changed? 14. If one rotates an image, which of its characteristics are changed?15. If one compresses an image, which of its characteristics are changed?

Self-study questions