Welcome to Alan's Hints 'n Tips
Sending pictures with an e-mail.
Picture formats to avoid - file types to use.
Why can't I just send any old picture?
Well, the easy answer to that is, "you can" ! BUT......
Have you ever had a picture sent to you by a friend and it is HUGE, like a few times wider than your screen can display in one go? I reckon you probably have. Annoying eh? You have to save it then look at through some graphic program so you can view it in a smaller size.
The problem with this sort of picture is two fold. It also takes a long time to send or receive via e-mail because the file size is LARGE.
How do I make my pictures economic to send to someone ?
First of all you need to know what things determine the picture's file size.
- Picture Resolution
- Number of colours used for image
- Format the picture is saved in
On a 14" or 15" monitor (screen) a picture which is scanned at 72 to 75 dpi, that's dots per inch, the screen image will appear virtually the same size as the original. In other words, if a postcard was scanned at 75 dpi it would appear on a 15" screen as near enough to the exact same size. This equates to 415 x 265 pixels on the screen for a 5½ x 3½ inch picture or for the metric people that's 140mm x 90 mm. This is probably a good size to send via e-mail for general family photos. Of course for wedding groups and such you may want to send bigger pictures.
See "Re-sizing your pictures" for more information.
Number of colours used for image
The number of colours used in a picture will depend on what the image is.
If it is a photograph it will probably be best at 16 bit colour - millions of colours which will be the default setting for pretty well all photographs these days.
The more colours used, the more information has to be remembered by the computer and subsequently included in the file when the image is saved.
Printed material is generally OK if as few as 256 colours are used. The number of colours use can be selected when saving your image. Try saving the image with a different name in case you want to go back a step. You can often use less 256 colours if you are designing something on your computer like a poster or card.
Some image formats only provide for 256 colours or less when being saved.
Format the picture is saved in
For a given image size, like 140mm x 90 mm for instance, the file size will also depend on the format it is saved in.
To give some idea you will see from the list below that a file which starts off as a .bmp (Bit Mapped Image) of 726K may be more econimically saved if the .gif (Graphic Interchange Format) is used and even better economy is achieved by saving as a .jpg which uses a compression format.
As an example, a picture in .BMP format with a file size of 726K, if saved in another format will reduce to file size as follows,
.BMP = 726K
.TIF = 386K
.GIF = 124K
.JPG = 64K
The size of the .JPG file will also depend on the amount of compression which is applied when saving. More compression means a reduction in picture quality while less compression effects the image quality less.
Note: Most modern graphic packages will allow you to load in one format and save in another. Programs like 'Paint' which comes with Windows doesn't have many save options even though it might load them OK it will only save as a .BMP (Bit Mapped Picture).
Animated .GIF pictures:
As you have found out, some picture files are animated. This is actually done the same as a Disney cartoon, frame by frame.... lot's of fun. Each frame is slightly different, or just two frames which alternate maybe. The individual pictures are combined (via special software) into a single picture which of course has to be larger than each of the single pictures..... In fact an animated .GIF using say 14 single files each of 2K combines to make an animated .GIF of 17K ( 14 x 2K = 28K) so it's not the actual total of all pictures, just keeps track of the changes between them in most of the software packages.
Some animations are not .gif files, they may have been saved complete with sounds as an executable file (.EXE) - these sort of files cannot be altered except by the person who made them in the first place. There are now a number of other formats for animation including "Flash" (.swf).
NOTE: Animations will only show ONE frame when a page is sent to your printer - it's generally the first frame.
