QCustomPlot Discussion and Comments

Hello :

I am trying to plot a Luminance histogram of an image. X axis will be intensity (0 to 255). Y axis will be number of pixels. The plot is created and working fine. I followed the example provided in Tutorials->Basic Plotting.

I am trying to create 5 different zones on the X axis namely 0-25 Black, 25-80 Shadow, 80-180 midtones, 180-130 highlights and 230-255 white. How do I create this so that it is visible on the plot

gopal

Do you mean an image representing the gradient? You could either just use a QCPItemPixmap and draw it yourself, or a QCPColorMap with according QCPColorGradient.

Actually 4 vertical lines on the same plot. This will represent 5 tonal zones Black, Shadow, midtones, highlights and white. The 4 vertical lines from X axis will be from coordinates (25,0), (80,0), (180,0), (230,0). And text in each tone zone as mentioned above