| In today's world it is important to understand | | | | be landscape rather than portrait. |
| image resolution and size, the basics are fairly | | | | How does Resolution affect File Size? The more |
| easy to get to grips with but the intricacies can | | | | pixels an image contains the larger the file is likely |
| be incredibly complex. The article this week has | | | | to be; this is due to the fact that storing |
| been inspired by many of our customers. On a | | | | information relating to 10 million pixels is liable to |
| weekly basis I get asked the same question 'how | | | | require more space than saving a lower resolution |
| many pictures will I be able to fit on this' when | | | | 1 million pixel image. |
| talking about the size of a memory card or USB | | | | Other important factors to consider are: |
| flash drive. I thought it was about time to spread | | | | File Format - Over the years there have been |
| the word. | | | | many different image file formats, each |
| What is Image Resolution? A pixel is a unit of | | | | introducing new advantages and disadvantages |
| programmable colour on a computers display and | | | | and covering them all would take an article in itself. |
| by combining many of them together we are able | | | | The two you are most likely to come in to |
| to create an image; by increasing the number of | | | | contact with when using a digital camera are JPEG |
| pixels, the resolution is also increased. Basically | | | | (smaller images that often include compression) or |
| resolution refers to the number of pixels used. On | | | | RAW (Completely unprocessed images files which |
| the whole, the quality of the image will increase | | | | are of a higher image quality but also substantially |
| with a greater number of pixels as we are able to | | | | larger) |
| store a greater amount of detail. | | | | Colour Depth - Along with the total number of |
| How is Resolution Measured? Resolutions are | | | | pixels that constitute an image, we also have to |
| usually expressed in one of two different ways - | | | | consider the potential number of colours each |
| either the total number of pixels used in the | | | | pixel could be. If, for example you save your |
| creation of the image are given or the pixel | | | | image as a 'line art' image where each pixel can |
| dimensions of the image are given. | | | | be either black or white then the amount of data |
| Most digital cameras express their maximum | | | | required to store this information is less than if |
| resolution in terms of megapixels (millions of | | | | you set a colour depth of 'true colour' where each |
| pixels) that can be used to create an image; an 8 | | | | pixel could be one of 16,777,216 potential colours. |
| mega pixel camera would be able to break a | | | | Compression - Many image formats, such as JPEG |
| picture down in to 8 million pixels hence giving a | | | | allow you to adjust the amount of compression |
| higher resolution that a 5 mega pixel camera. | | | | that is utilised when saving the image. |
| The resolution of a computer image on the other | | | | Compression can work in a number of different |
| hand is usually expressed by giving the number of | | | | ways but ultimately it works to minimise the |
| pixels present on a line and the number of lines | | | | amount of data required to save the image. This |
| used in the image. For example, an image | | | | is usually achieved by looking for areas of |
| measuring 1600 x 1200 would contain 1600 pixels | | | | commonality (for example a shape or pattern) |
| per line and a total of 1200 lines giving a total of | | | | and saving the description of that area which the |
| 1,920,000 pixels (1.92 mega pixels). As the image | | | | computer can then later reproduce when reloading |
| contains a greater number of horizontal than | | | | the image rather than defining each individual pixel. |
| vertical pixels we can assume this picture would | | | | |