I am new to this site but have been doing digital photography and computer graphics for a number of years. I know there are many free or shareware programs out there to resize and convert graphics images. However, there are also many powerful graphics programs which are also very inexpensive! After getting one, I can assure you that you will wish you had had one all along! One excellent program for converting many graphic file types, resizing images, cropping images, doing overlays, etc. is Photo Studio by Arcsoft. The last version (Vers. 3) I bought was under $40.
Another indispensable graphics handling program is Thumbs Plus by Cerious Software, which I have also used for years. It is excellent for tracking images (& other special files) on your computer, as well as making thumbprints for quick locating, for batch resizing & photo editing, for printing image catalogs, and for printing custom photo albums, and for computer slide show viewing. I believe my last version (Vers. 4) ran about $35.
Other general info: most newer digital cameras will allow you to take the initial photos in various levels of JPEG compression. For most computer viewing purposes (& for emailing), I recommend a setting of under 1.2 Megapixels at medium JPEG compression, so that the digital photos average about 250KB initially.
I usually re-crop them, resize them, and sometimes even increase the JPEG compression with a lower Quality Percentage (under 80%) if I want them to be under 50KB to quickly upload for emailing.
One other note: I have mentioned only JPEG format, as it is the best for emailing compressed color images. The bitmap images (with .BMP extensions) created with Microsoft Paint are not compressed---the good quality 250KB JPEG images with average compression would be about 3 MB in bitmap format!! One can convert also to another popular web page and emailing format called GIF-- it is a good format for sending B/W and also color graphics drawings & charts (not good for photos). If you want to provide high quality compressed images to Macintosh users, you can convert the image to TIFF format.
Well, I wanted to share some of what I have picked up over time in handling computer graphics, and I hope I didn't bore you but hope this info is useful to those of you new to computer graphics.
Regards to All,
Glenn
Bellaire, TX