Due date: Thursday, January 20.

Ex. 1 Here is a table of correspondence between the RGB, HSV, and HTML color representation systems.
 

Color	Aspect	RGB	HSV	HTML
black		0, 0, 0	0, 0, 0	"#000000" = 0, 0, 0
white		1, 1, 1	0, 0, 1	"#FFFFFF" = 255, 255, 255
gray		0.3, 0.3, 0.3	0, 0, 0.3	"#555555" = 85, 85, 85
red		1, 0, 0	0, 1, 1	"#FF0000" = 255, 0, 0
yellow		1, 1, 0	60, 1, 1	"#FFFF00" = 255, 255, 0
green		0, 1, 0	120, 1, 1	"#00FF00" = 0, 255, 0
cyan		0, 1, 1	180, 1, 1	"#00FFFF" = 0, 255, 255
blue		0, 0, 1	240, 1, 1	"#0000FF" = 0, 0, 255
magenta		1, 0, 1	300, 1, 1	"#FF00FF" = 255, 0, 255
light blue		0.6, 0.6, 1	240, 0.4, 1	"#9999FF" = 153, 153, 255
light orange		0.9, 0.5, 0.3	20, 0.67, 0.9	"#E68055" = 230, 128, 80

Complete the following c++ file performing a conversion between these 3 formats.
convertrgb.cc
This file does not require any special library and should compile with a simple g++ command.

Hint:
0.67 = 1 - (0.3 / 0.9)
20 = 0 + (0.5 - 0.3) * 60 / (0.9 - 0.3)

Hint
For the transformation from HSV to RGB, you can find the maximum of the r, g, b values directly from the v value. The formula
c.s = 1-mn/c.v;
can be reversed to compute the minimum of the three values, mn. The offset can be computed as the difference between the angle h and the dominant component, based on the quadrant. For example, if the angle h is between 120 and 180, then the offset if h-120, while if it is between 180 and 240, then it is 240-h.

Then the formula
offset = (md - mn) * 60 /(c.v - mn);
can be reversed to compute the median of the 3 values, md.

Last, suppose that we have mx, md, and mn, the three values in this order. The way they are assigned to the rgb values also depends on the quadrant. For example, if the angle h is between 60 and 120, then mx will be assigned to g, the median value will be assigned to r, and the smalled value will be assigned to b.

In addition, you will probably need to consider the special cases that result in the denominator in any of the formulas you have to be 0. Those need to be considered separately before.

Ex. 2 In this exercise you will experiment with image representation and color

• Retrieve an image from any source (web, scanner)
• Open the image with the Gimp (available on the Linux machines) or Photoshop or any other editing program. Modify its colors using the HSV system (in the Gimp under Colors menu). Save the file as a bitmap or TIFF file. Modify the colors using the HSV mode (right click -> Image menu ->Colors -> Hue-Saturation).
• Save the file as a png with a level of compression 9 and with the level of compression 5. Save it also as a jpg with two or 3 different settings for the quality (85 would be standard). Write in your email the sizes that you got for each of these file types and if you observe any different in the quality of the image if you open it with the image viewer or preview afterward (on Linux you can use the command "display"). Send me one of the files in jpg format.