C# application - Convert the image to the SQL tables and simple operations on colors

Functional requirements: 1. Layers (analogous to graphics programs) - add and remove layers - each layer has attributes: name, is turn on/off, order (z-index) - for each layer user can load png file (high resolution 10000x10000px or larger), each pixel of the image should be saved in a table (position x, y, color (RGB), layer ID) 2. Operations on layer - for each layer (separately) should be available the following operations: - replacement of one color to another, - conversion of a range of colors to a single color - remove color (becoming transparent) - report (list): color, number of pixels in the color 3. Preview - a simple view of all active layers including the z-index parameter - preview should be limited to a selected area eg. 100x100px - preview should be displayed in zoom mode - each original pixel is represented as 5x5px square in the original color (the color of the top layer, unless the top layer is transparent) - ease of navigating: move left, right, up, down Technical Requirements - .net 4.0 or 4.5 (c #) - Database MS SQL 2008 or later - Database access layer: (entity framework 6 or nHibernate 3) or later - English-language names in the code - Allowed only free external libraries Contractor agrees to provide: - Full source codes - SQL scripts to create the database - External dlls