Unit 8 3º eso digital images
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Transcript of Unit 8 3º eso digital images
THE DIGITAL IMAGE
3rd ESO Visual Arts, Teacher Simone
The digital image
What is a “digital image?”
The digital image
A digital image is an image that is created, stored
or manipulated through a computer or another
digital support. It is seen on a screen or monitor.
Digital images
In our time, digital images are a large part of the
images we see on a daily basis– on a computer
screen, in the cinema, in television, in video games,
etc.
What do we know about Digital
Images?
Megapixels?
Pixels per inch?
Resolution?
Depth of color?
Bitmap images
Bitmap images
Are digital
photographs.
They’re
formed by
small squares
call pixels,
similar to a
“mosaic”
Bitmap images
The images
contain a
wide variety
of colors and
tones.
Bitmap images
These images
lose quality as
we “zoom”
Bitmap images
In a bitmap image,
each pixel is
formed by three
components: Red,
Green and Blue
(RGB).
Each pixel is coded
separately by the
quantity of each
color found in the
pixel.
Bitmap images
When printing
a bitmap, the
colors
components
are Cyan,
Magenta,
Yellow and
Black (CMYK).
That is why, in
your printer,
there are 3
color
cartidges and
1 black.
Vectorial images
Vectorial images
Are formed by segments and polygons of color.
They are coded by formulas.
That is why they take up little space on a digital support.
Vectorial images
They do not
lose quality
when we
zoom.
Bitmap images vs. Vectorial images
Bitmap images vs. Vectorial images
Bitmap images vs. Vectorial images
Bitmap images vs. Vectorial images
Bitmap images vs. Vectorial images
Pixels of colors
Great tonal variety
Take up a lot of space
Lose quality with zoom
Photographic use
Segments and polygons
Coded by formulas
Don’t occupy much space
Don’t lose quality with zoom
Publicity use (logotypes, etc)
Bitmap images Vectorial images
Bitmap images vs. Vectorial images
Bitmap images vs. Vectorial images
Bitmap images vs. Vectorial images
Let’s get to work
Look at the vectorial image.
Transform the image into pixels, just like a bitmap.
Remember that each pixel must be a complete
square, not part of a square
Use pencil colors, and color mixing, to replicate the
image
Here is your vectorial image…
Let’s review!
What is a digital image?
What is a bitmap image?
What are some differences between bitmap and
vectorial images?
What is a pixel?
Quality of digital images
Resolution
Detail or quality of an image
Amount of PIXELS PER INCH (ppi)
Key values:
Computer screen: 72 ppi.
Printer: 600-1200 ppi.
Digital cameras: 1 MP = 1.000.000 ppi.
Resolution
Bits
The number of distinct colors that can be
represented by a pixel depends on the number of
bits per pixel (bpp).
A «bit» is short for BINARY DIGIT.
Bits
What is binary code?
A language used in computer programming.
Every bit can represent two values. In binary code,
this is the 0 and the 1.
Color Depth
More bits=more colors
1 bit= 21= black and
white
2 bits= 22= 4 colors
8 bits= 28= 256 colors
24 bits= 224= 16
million colors
Color modes
Monochromatic
1 bit: 2 colors 8 bits: 256 col
Greyscale RGB
8 bits: 256 16 bits: …
Guess the number of bits
1 bit
2 bit
4 bit
24 bits
Image formats
BMP (Bitmap)
High quality
Large files
GIF
Low quality (maximum 256 colors).
Small files
JPG
High quality (16 million colors)
Formato comprimido: pierde calidad
TIF
High quality
Large files
PNG
Low quality (maximum 256 colors).
Usually internet images
Take a portrait picture
It can be of yourself or a friend
You can use photobooth or the camera
You musn’t use ANY color effects in photobooth
The photo must be in color and have good illumination
Exercise 1. Change the color mode
To do this exercise we will use: http://pixlr.com/editor/
1. Select a photograph
2. Open the photo in pixlr
3. Change the photo to
greyscale. Click > Ajustes
> búsqueda de color
4. Save the file. Archivo >
guardar
Exercise 2. Change the resolution
To do this exercise we will use: http://pixlr.com/editor/
1. Open the same photo in
pixlr
2. Click Filtro > Pixelizar
3. Save the file. Archivo >
Guardar
Exercise 3. Change the tone
To do this exercise we will use: http://pixlr.com/editor/
Tone is the amount of a
certain color in a photo.
1. Open the same photo in
pixlr
2. Change the tone. Click
Ajustes > Tono y
Saturación…
3. Save the file. Archivo >
Guardar
Exercise 4. Change the saturation
To do this exercise we will use: http://pixlr.com/editor/
Saturation is the intensity
of the colors in the photo
1. Open the same photo in
pixlr
2. Change the saturation.
Click Ajustes > Tono y
Saturación…
3. Save the file. Archivo >
Guardar
Exercise 5. Change the luminosity
To do this exercise we will use: http://pixlr.com/editor/
Luminosity is the brightness
of the photo
1. Open the same photo in
pixlr
2. Change the luminosity.
Click Ajustes > Brillo y
Contraste…
3. Save the file. Archivo >
Guardar
Exercise 6. Change the contrast
To do this exercise we will use: http://pixlr.com/editor/
Contrast is the amount of
difference between the
lights and darks of a
photo
1. Open the same photo in
pixlr
2. Change the contrast.
Click Ajustes > Brillo y
Contraste…
3. Save the file. Archivo >
Guardar
Exercise 7. Use other filters and
adjustments To do this exercise we will use: http://pixlr.com/editor/ Filters are used to create
other effects in a photo
1. Open the same photo in
pixlr
2. Change adjustments and
filters. Click Filtros or
Adjustes
3. Save the file.
Exercise 8. Combine the 12 images
Combine all of the images
in one image
1. Open all the photos in
pixlr
2. Click Imagen > Tamaño
de lienzo…
3. Change the size of the
canvas to fit 4 x 3 photos
4. Save the file.