exercise 5.file types and sizes

Name
	§ This is a formative assessment instrument § You must be rated ‘Competent’ in this assessment item.
Learning Outcomes	Learning Outcome 6 - Identifying and define a range of file types and describe their uses, and compare and evaluate methods of uploading digital files using general operating systems and dedicated imaging software.
Tasks	1) Copy the file ‘Img 1 – Ex 5 – Image.tif’ from eLearn to ‘yourname-Ex5’. (Remember to delete this file when you have completed this exercise). 2) Open the file ‘Img 1 – Ex 5 – Image.tif’ in Photoshop and do the following :- Select ‘Image -> Image Size …’ :-

1. Width of the image in pixels? 2500
2. Height of the image in pixels? 2000
3. Calculate the size of the image in Megapixels? 14.3m
4. What is the specified resolution of the image? 300
5. Width of the image in cm? 21.17
6. Height of the image in cm? 16.93

Select ‘File -> Save As…’ and save the image in the following formats. Name the files to clearly identify them.

After each save close the image and reopen to save to the next format. Use the Finder/File Browser to record the sizes of the files created.

1) The original .tif file? 15.1 mb
2) TIF file using LZW compression? 10.6mb
3) Photoshop .psd file? 15 mb
4) Jpeg file – Quality level 1? 4.2 mb
5) Jpeg file – Quality level 10? 1.9 mb
6) Jpeg file – Quality level 5? 680 kb
7) Jpeg file – Quality level 1? 401 kb
8) GIF file – 256 colours – no dithering?	2.9 mb
9) GIF file – 256 colours – diffusion dither?	3.5 mb
10) GIF file – 16 colours – diffusion dither?	1.4 mb

Select ‘Image -> Mode -> Greyscale’ to convert the image to a grayscale image & save as

11) TIF file (no compression)? 5.1 mb

Select ‘Image -> Mode -> Bitmap’ to convert the image to a bitmap image & save as

12) TIF file (no compression)? 852 kb

3) Discuss the following with the class and post the answers on your blog :- a) Explain the difference in the sizes of the two tiff files in steps 1) and 2). b) When saving a jpeg file what two things change when you select a different quality factor ? c) What is ‘dithering’ and why is it used ? d) Explain the difference in size between the greyscale tiff file and the original tiff file.

Exercise 4 – Bit Depth and Colour Modes

1) Download the file ‘Img 1 – Exercise 4’ from eLearn and place it on the desktop. (Remember to delete this file from the desktop when you have completed this exercise).

2) How big is an A4 page in cm? 29.7 x 21

3) Open the file ‘Img 1 – Ex 4 - Granger-Rainbow.jpg’ in Photoshop :-

4) Select ‘Image -> Image Size …’ and ‘Image -> Mode’ and answer the following questions :–

Image size in cm? 29.63 x 20.32

Pixel Dimension (W x H)? 3500 x 2400

Image size in megapixels? 3500 x 2400 / 100 000 = 8.5

Resolution of the image(ppi)? 300

Image size in megabytes? 24 m

Colour Mode? RGB colour mode


Bit depth 8/bit channel

Hint: Use the Status line to display the image size – use the number on the left.

5) Use the ‘Image -> Mode’ menu to select the following modes / bit depths and fill in the table for each case listed. (Note: Use ‘Undo’ or the History list after each case to return to the original image state) :-
Colour Mode Bit Depth per channel Total Bit depth No. of available colours
RGB 8 24 16.8 mil 24
RGB 16 46 2x8x10(14) 4.81
CMYK 8 32 4.3 mil 32
GS 8 8 256 8
Bitmap # 1 1 2 1
Indexed Colour – 256 colours N/A N/A 256 8

Exercise 2- Image Basics

1. Width of the image in pixels?
2000 pixels
2. Height of the image in pixels?
1500 pixels
3. Calculate the size of the image in Megapixels?
3 Mp
4. What is the specified resolution of the image?
300 ppi
5. Width of the image in cm?
16.93 cm
6. Height of the image in cm ?
12.7 cm
Turn OFF the ‘Resample Image’ option and change the Resolution to 150 pixels/inch.
7. Width of the image in pixels?
1000 pixels
8. Height of the image in pixels?
750 pixels
9. What is the new Width in cm?
6.67 cm
10. What is the new Height in cm?
5 cm
11. What is the image size in Megapixels?
0.75 Mp

Change the resolution back to 300 pixels/inch
Turn ON the ‘Resample Image’ option and change the Resolution to 150 pixels/inch.
12. Width of the image in pixels?
500 pixels
13. Height of the image in pixels?
375 pixels
14. What is the new Width in cm?
8.47 cm
15. What is the new Height in cm?
6.35 cm
16. What is the image size in Megapixels?
3.46 Mp

Question:
Where else in Photoshop can you find the above information ? INFO PANEL / STATUS BAR :
1. My image is 2100 pixels wide and 3300 pixels high.
a. What is the image size in megapixels ?
2100 x 3300 / 1000,000 = 6.93mp
b. What would be the physical image size at a resolution of 300ppi ?
2100 = 7"
300ppi
7" x 11"

2. My image is 2000 pixels wide and 3000 pixels high.
a. What is the image size in megapixels ?
2000 x 3000 / 1000,000 = 6 MP
b. What resolution would I need to print at to create a 8” x 12” print ?
2000p. = 250 8"

3. I want to make an A4 print with a resolution of 300ppi.?
a. What is the image size in cm ? 21 x 29.7
b. What is the image size in inches ? 8.3 x 11.7
c. Rounded to the nearest inch, what would the pixel dimensions be ?
8 x 12
a. What is the image size in megapixels ?
7.9 MP

Exercise 1 – Image Uses

1, types of photograpy:fasion

photo journislm

wedding

maco

documentry

architecture

traval

food

family

light painting

under water

time lapse

astro

pet

2, list potential employers: light painting

magazine edditors

brochures

grahic desiners

car companys

web desiners

bands

3, ways they would be able to use the image:

bill boards

busnies card

imageing in magazines

album covers

graphics

comercals

4, size and quality of reproduction:

medium quality 5 m x 10 m

hight quality 5 cm x 8 cm

medium quality A4 paper glossy cover

hight quality 8 cm x 8 cm rough finish

hight qulity digital 24 inch