Lesson 1 – Objectives

DiDA – Image manipulation

Lesson 1 – Objectives

• Understand what a bitmap is• Understand what image resolution means• Using selection in GIMP• Using layers and background erasing to create

a combined image


Bitmap images

• This is a family of images which are made up of tiny dots.

• Each dot will have a different colour.• Combined they produce an image• All photos and most images from the internet

will be bitmaps.


Jaguar at 50% (or half the original size)


Jaguar at 200% (double size)


Jaguar at 1000% (or 10x zoom)


Pixels and resolution

• Notice the dots? These are known as pixels.• The more pixels on the screen the higher the

quality. • We measure pixels by counting the number of

pixels vertically and horizontally.• This is known as resolution.


Low resolution Vs high resolution

128 x 128 1600 x1200


Resolution in google

Each image has it’s resolution under it in google!!


Bitmap file formats

• BMP – Windows bitmap (very large files)• JPG – Jpeg. These images are heavily

compressed and sometimes loose quality.• GIF – Used for drawings. Can only have 256

colours!! This is known as indexed. Supports transparency

• PNG – Good mixture of compression and quality. Supports transparency


Image manipulation

• Programs such as GIMP, photo shop and paint shop pro are known as image manipulation programs.

• They allow bitmap images to be manipulated.• They are essential when creating high quality

publications.


Your task today

• You are going to create a film poster.• Your poster will be made in sections in GIMP• We will break your poster down into the

following sections– Main foreground image– Background– Title + slogan– Other text (like actors etc)


Sections

Foreground image

Title

sloganExtra text

Background


Getting started

• Your film must be made up. • It can be a parody of a old film or a brand new one• Decide on this first before you continue.• Take a few minutes to decide this. Decide– On the title– On the genre (rom com, thriller, sci-fi etc)– Actors

• Be imaginative. For example you could have yourself as the main actor/actress!


Getting the foreground image

• Now find a high quality (high resolution) image to act as the foreground.

• This could be a photo if you want to use yourself or a friend as the main character.

• It does not have to be a person, it could be a car or anything which fits in with your film.


Task

• Find 3 high resolution images to use for your film poster.

• Note – Do not worry about your choice. The key here is practicing skills!


My main image


Removing the background


Tools to use

The “portrait” tool. To use this you must –1. Draw roughly around the shape you want. Make sure

you create a complete loop.2. Draw on the foreground image. The background

should turn blue.3. Any blue parts on your main image just draw over

them!4. Any parts of the background which are NOT blue

then you must hold [CTRL] on the keyboard and then draw over it.


More tools

The magic wand tool (or fuzzy select) will select areas which are similar in colour. This can be used to remove areas which might have been missed by the portrait tool

This tool selects ALL colours which match the one you click on. Can be very useful!


Video help!

• You can watch this video to help!


Changing faces

• Next we are going to replace the face. We need to find a face which is looking in the same direction in order for it to “work”.


Removing the face

• Again you can remove the background AND the body using the same tools.


Smoothing

• If you get any “jagged” edges you can smooth them out using this tool


Copy and paste

Jonathon Ross is now Neo! This does not look great. We need to get the gun in front of Mr Ross.


Duplicate the background

Make a copy of the background and add it as a new layer. This new layer will be the “gun”.

You can duplicate a layer by selecting it and click on the icon shown below


Move the gun layer


Showing the face underneath!

• You can rub out Neo’s face to get Jonathon’s instead.

• Again you can use the skills already used to help.

• You will need to smooth things out after editing as it is easy to make mistakes!


Note!

• This is MUCH easier with high resolution images.

• If you find the image is too difficult then choose something else.

• There is a limit on how much editing you can do in order to improve an image.


Version 2 – Gun in front of Mr Ross


Step 3 – Remove old parts of neo from the background.


Task

• Remove the background from a second image• Combine the two images together• Extension – Save the image as a PNG file and

then import the image into publisher. Complete the poster in publisher.

Lesson 1 – Objectives

Documents