Hey It NOT ISSUES But i need colormap Add cubehelix

[KristapsSDRSharp]

[f4exb]

It is pretty difficult to retrieve values from a picture. In SDRangel color maps are stored as 256 (R,G,B) floating point values (0.0 to 1.0) from lower (left on the picture) to higher (right on the picture). If you can provide these values it will be no big deal to add this color map.

[f4exb]

This can be done in Python...
Firstly install pillow:

pip install pillow

Then this snippet should print out the colormap structure to be inserted in sdrbase/util/colormap.cpp:

from PIL import Image

im = Image.open('cubehelix.png') 
pix = im.load()
xsize = im.size[0]

print("const float ColorMap::m_cubehelix[m_size] =")
print("{")

for xi in range(256):
    x = int((xsize/256)*xi)
    colortuple = pix[x, 0][:-1]
    rf = colortuple[0] / 256
    gf = colortuple[1] / 256
    bf = colortuple[2] / 256
    print(f"    {rf:.4f},   {gf:.4f},   {bf:.4f},")

print("};")

[f4exb]

The explanation that goes with this palette seems to be here: https://people.phy.cam.ac.uk/dag9/CUBEHELIX/ Could be nice indeed.

Alternatively it has a link to a Javascript page that can also print out the RGB values: https://people.phy.cam.ac.uk/dag9/CUBEHELIX/cubetry.html

[f4exb]

Two new colormaps:

• cubehelix: derived from the attached image which has linear grayscale progression
• cubegamma: calculated with the javascript app applying a gamma factor of 0.4 to accentuate weak signals