From binary to bitmap and back

In this lesson

Draw the image that a given binary pattern represents, and write down the bit pattern that represents a given simple bitmap - reading the grid in the right order, grouping the bits by the colour depth, and using only the colour key supplied.

What it covers

• Given a binary pattern that represents a simple bitmap, DRAW the resulting image as a series of pixels (AQA's own scope wording)
• Given a simple bitmap, WRITE DOWN a bit pattern that represents it (AQA's own scope wording)
• The reading order, stated as a rule and never varied: start at the top left, work along the row, then drop to the start of the next row
• Splitting the bit string into groups the size of the colour depth - one group per pixel, in order
• Using the colour key GIVEN in the question and nothing else, however obvious another scheme looks
• A 1-bit grid is two colours; a 2-bit grid is four; the group length is the colour depth, which CS03-01 defined
• The arithmetic check that catches most slips: width x height pixels means width x height groups, so the length of the bit string has to come out exactly

Key words

On the specification