When we talk about photo editing, processing and retouching, Photoshop is one of the most promising software comes to our mind. But this excellent tool also has a few drawbacks such as expensive  cost, complex if you are first time user, consume lots of computer resource etc…

Also read: how to make a photo collage

Here I have listed some free software which could replace Photoshop. They are lightweight, and relatively easier to use than Photoshop.

gimp
1. GIMP: GIMP is Photoshop nearest competitor. Provides advanced features and options, very similar to those found in a professional Software. It can be installed on both the computer and a USB. It is open source and available for free to download for different platforms.

paint_net
2. Paint.Net: For some users it is the best photo editing software available for free. Their main advantage is that it is full of plug-ins that provide it with additional features with a host of special effects.

picasa
3. Picasa: Picasa is Google’s program for photo editing. Organize, edit and share photos in an extremely simple and affordable manner.

pixia
4. Pixia: Although this software is more geared towards the drawing, its features and simplicity makes it good alternative of photo editing software. It comes with lots of filters and settings  that will give life to your photos.

art_weaver
5. Artweaver – You need .NET Framework to use Paint.Net, If you don’t want to install any framework, or simply would like another option other than Paint.Net you should have a look at this.

Although it is more focused on being a painting program, it has a very good array of image adjustment tools. Artweaver also has a curves and levels tool that works a little better than Paint.Net, in my opinion.

LunaPic
6. LunaPic: A fabulous online editor. In addition to complimentary set, it requires no installation or registration. The amount of features and options offered make it a very attractive option. 

ImageForge
7. ImageForge: Although it has a paid version, ImageForge Standard Edition is available for free and can be download from their website. Free version is available with limited features. You can keep the free version and use it as photo editing program by default.

PhotoFilter

8. PhotoFilter: Free, intuitive and with a lot of options that help editing with different options, saving the user a lot of time.

light_box_image_editor
9. LightBox Image Editor  is a small and light weight program with very attractive user interface that you will find very useful. All functions are straight forward, and offers intuitive slide-bar adjustments for your images. It also have functionality to spilt the screen view so that user can compare between after and before image.

photoPlus
10. PhotoPlus: If you want a photo editing software with basic functionality and easy to use, PhotoPlus 6 can be the your best friend. However, if you have to buy commercial license if you want to use it for non personal editing.

photoScape

11. PhotoScape: A very functional photo editor with full of different features. Simple and easy for first time user to edit  picture and give professional touch.

vicman
12. VCW VicMan: Another editing program very intuitive and with so light weight. It’s very basic but it meets the minimum functions to edit a photo, rotate, crop, adjust color, add text and watermarks.