The main problem comes when you want to manage these photos via Internet . Its weight can cause problems when trying to attach in an email or upload to a social network , for example. Web services and social networks often have limitations on the maximum sizes of images and attachments, so that the operation to attach or upload can sometimes be impossible.
There are some solutions to overcome this problem and reduce the weight and size of these images, as indicated from Consumer . Keep in mind that the reduction involves a loss of information of the image.
In Windows you can use Paint, very basic but can help those less initiated in digital retouching. Account in the 'image' with the option to collapse and expand an image by introducing horizontal and vertical values. With a value of 50% horizontal and vertical, the image is reduced to a quarter. Other free applications for this operating system are Light Image Resizer and Fotosizer
In Mac OS X , when you open any image with the application 'Preview' from the 'Tools> Adjust Size' is possible to indicate the new dimensions of the image. This application also automatically calculates the new output file size, resizing and optimizing the selected image. In the case of decreasing the weight of a batch of images, one option is to create a workflow tool for Mac OS X. Automator
Picasa from Google account, among other features, with the option to optimize the size of the images. Flickr is not the case, which resizes images uploaded to a maximum and then makes replicas in different sizes, so that later propose several formats for each picture.
Keep in mind that in some cases these services only perform the function of optimizing the size of the image , but without affecting its original size. That is, only made the option to compress an image by using proprietary algorithms, in order to provide a optimized compression that some desktop applications. This is the case of web services like those provided by Image Optimization or Jpegmini. The latter is a free service that can be used without registration, promises a five times lower in reducing the file size without losing image quality minimum. For registered users, has other features like the option to temporarily gain for optimization albums and share images on platforms such as Picasa and Flickr.