Unit 30: Task 8: D2

Task 8b

Describe and evaluate the impact that file format, compression techniques, image resolution and colour depth have on file size and image quality.

print screen 1: file types JPEG, GIF and PNG
print screen 2: compression techniques, all JPEGS at different quantities
print screen 3: colour depth, all Gifs and different colour amounts.

File type: This screen shot shows the different files types; the original image is in the top left hand corner, the JPEG image can be seen in the top right corner, the bottom left shows GIF and the bottom right shows a PNG-8 file format.  The file format that is PNG-8 shows mottling around the image which shows clear blurred effect surrounding the image if you look closely at the image it looks distorted and pix-elated. PNG holds a better quality closest to the original image and is capable of displaying more colour than JPEG.  In comparison to GIF a JPEG is capable of displaying more colours, however when compressed a JPEG file no longer looks as clean and crisp within the photograph. Gif image file formats have a cleaner display when saved however they contain less colour.  

JPEG - will take up 43.94KB
GIF - will take up 159.5KB
PNG-8 - will take up 157.9KB
Original - will take up 732KB

Compression techniques: This screen shot shows the various compression techniques which are available within a JPEG file format. The top left hand corner displays the original image as has been shown in the previous screen shot, on the top right hand corner the image displayed shows a JPEG image file at the highest quality that it can be, at the bottom left it shows the image in a medium quality compression and at the bottom right it the 4-up display shows a low quality JPEG compression image. Compression reduces the amount of space the file will take up on the disk therefore it is squeezed down so that it does not use vasts amounts of disk space. JPEG which is lossy compression shrinks down the image file but with little noticeable effect so the image will remain fractionally the same before it is compressed and saved. Some lossy compression seen with the lowest quality appears jagged and pixelated in areas as the resolution is poor.  The file with the highest quality will require the greatest compression will reduce the file's quality. 

Colour depth: This screen shot displays the colour depths available in a GIF file format and which one will have the best resolution when saving the image. Like the previous two screen shots the top left hand corner is the original image, in the top right hand corner a GIF file with the colour depth of 256 can be seen, in the bottom left a 64 colour depth file and in the bottom right a 16 colour depth file. As seen in the screenshots the GIF file that only has 16 colours has a poor resolution and a weak finish in comparison to the original image it is not as vivid and bold with the colours. The 256 colour GIF displays the vivid colours rather like the original image and has a higher resolution when compared to the 64 colours. When there are more colours (256) being used it also results in a really large file size of 3,786 bytes in comparison to 16 colours which will only have a file size of 1,393 bytes which has a poorer quality than the GIF shown at higher depth.

JPEG files are used mainly to compress images so that they will take up less space when saved onto a disc or hard-drive, to create a small file size the lossless image with have a low quality however to get a good quality file with high resolution the file will essentially be larger and take up more space. It should not be used when creating graphics or texts and only used for photographs.

GIF files are mainly used when regarding colour depth as at and 8-bit colour depth the image will use 256 colours but will loose quality when saved, that is why it is best that GIF's are used mainly for logo's as they require minimum colours and can be saved and compressed into a file that will be smaller than a JPEG and will contain clearer colours than a JPEG image. 

PNG files are used as a substitute for GIF files and can create a transparency to the image and have a small compression size, but will have a slow rate when read and written. It is fairly like a JPEG file as it uses lossless images at a fairly resonable quality. 

Unit 30: Task 7: D1

Task 7a

Describe and evaluate the ongoing developments in these printing/output techniques:

1. Vinyl cutters and laser cutters for signage.
2. Inkjet & wide format printing for bitmap displays and posters (see video below).
3. Laser printers for leaflets and flyers.
4. 3D printing

Make sure you cover how this has affected the creation of graphics.

All these printers below create a physical copy of your image.

1. Vinyl cutter and laser cutter for signage:-

They have now been developed so they can be printed any colour desired straight away so all you will have to do is press it directly against the desired area and it will sit on the wall. You used to have to remove the excess vinyl but now you can directly place it on the wall without having to remove the segments that can be found in the o's and a's etc.  You are capable of vinyl wrapping, specialist printers that print onto plastic vinyl e.g sky vans, they print it directly onto vinyl and sick it straight onto the van. They are weatherproof and can last for the life of the van, the graphic stays vivid and the same. This has only came about in the last couple of years.Laser cutters are mainly used for plastics and signs made from perspex. They have only just came into effect and are fairly expensive. Advanced to vehicle wrap and you can use laser cutters for signage. Vector graphics as the cutter uses the line of the vector to cut the image out.  Shopping signs are made by sending the graphic as an eps file using Inkscape, this helps allow you to embed images into the format. This will produce a vector image of your design which will have to be saved as an EPS file, it must be vectored, expanded and live traced before the file can be directly sent to your vinyl cutter. The maximum thickness you can cut with a laser cutter can go to 5/8" with accuracy of up to 0.001 on materials such as wood and bricks. 

2. Inkjet & wide format printing  for bitmap displays and posters:-

They have to be created as a vector image so that it will not lose focus and resolution. It can be put on any material directly for example plastic, glass etc. They are highly expensive and have been developed to appear directly on the material instead of printing it on paper, putting a layer of adhesive under the paper then sticking it onto a board and then laminating it so the colours will not run of some sort for large scaled bobble images. This would have been a long process and the improvements allow you to print directly onto any substrate under 50cm thick which is weatherproof, durable and can last many years. The are highly expensive as you are printing directly onto your substrate material. They are extremely effective and appeal to observes and passers by. The printer use to move in the machine but now only the head will move on a inkjet printer. Can use a JPEG which is high resolution or a PDF graphic that includes vector and bitmap images. Prints produced by an inkjet printer are used for posters and other general copies etc. The image must be of high resolution for large formats such as   logos and pictures otherwise they will become pixelated and will not be as clear and vivid for posters, which will be displayed on billboards etc.

3. Laser printers for leaflets and flyers:-

Laser printers essentially create a colour photocopy of your image. They also allow you to complete duplex printing onto both sides of the paper without it exiting the machine. Previously it would have had to have been removed and taken in again so that it prints both sides. You can get it stapled and collated into a book using the printer saving you the trouble from these time-consuming tasks. 
PDF which uses both bitmap and vector graphics. To cut shapes out the shape must be a vector format so that it can cut out the pathway which allows it to make up the shapes that have been converted into laser paths so that they can be sent to the laser printer and grafted on the material desired. For scanned images the laser printer uses bitmap images which only involves black and white pixels, the BMP files for bitmap images can be sent directly to the laser cutter to be crafted onto the material. Laser printers are ideally used for thick card and heavy paper so that they can produce good quality leaflets and flyers. The average thickness for small art displays such as leaflets are 300 PPI, as they cannot process thicker paper as a BMP file.

4. 3D printing:-

It is an ongoing development as it has newly been made accessible to the world and is further developing overtime, creating improvements. 3D printing is capable of printing at high speeds, many various graphics in a 3D format. It uses a STL format which is a process where the real object is created in 3D, OBJ formats allow the 3D printer to read the information that has been sent and visually create the image. 3D printers work by creating a visual image using a CAD format which helps create a 3D format of the image you have printed, by using a 3D modelling program the scanner makes a 3D copy of the object. The file must be made in the modelling program which slices the image into layers. These layers are then separately sent to the 3D printer, the printer itself blends all the layers together forming the 3D object.  There is also printing known as additive manufacturing which is also growing from the prototypes which had been previously made which are now capable of producing various products for car industries and medical purposes. 3D printing is being developed to create toys and furniture business, to predetermine plans for products that can be made in the near future.