Detecting Image Brightness/reflectance

ktgerloff
ktgerloff
in Image-Pro Plus General Discussions
How can I measure the brightness/reflectance of a certain part/section of an image? We are using Image Pro Plus 6.3.

Answers

  • YuriG
    YuriG
    You can use line profile, mouse cursor (intensity is reported in the status bar) and if you segment the objects, the brightness is reported as Den./Inten.(mean) in the measurements table.

    You may also check various tutorials in our media library http://www.mediacy.com/resources/media 

    Yuri
  • ktgerloff
    ktgerloff
    YuriG said:
    You can use line profile, mouse cursor (intensity is reported in the status bar) and if you segment the objects, the brightness is reported as Den./Inten.(mean) in the measurements table.

    You may also check various tutorials in our media library http://www.mediacy.com/resources/media 

    Yuri
    Hi Yuri,

    Thanks for your quick reply. I have a follow up question. How do I use the segmentation tool in conjunction with the line profile tool? The output's units in the measurements table is "intensity" in the y-axis and "distance (pixel)" in the x-axis, and I'm not sure how to interpret these units.

    We are working with images of leaves. I am trying to correlate the presence of leaf hairs to image brightness, so that we can measure leaf hair count without actually counting all the leaf hairs (which would be tedious/impossible). We would like to do this by establishing an area of interest on the leaf and possibly comparing to a white image as a reference/baseline value. I've determined how to establish a reference value using the user manual, but I am still unsure how to interpret the results, or if this is even the best way to you about doing this.

    Thank you for reading.
  • YuriG
    YuriG
    Intensity is the measure of Gray level pixel values. There is Intensity calibration available to convert gray levels to appropriate units. Though reading your further comments I think that you don't really need any intensity measurements, you just want to segment the leaves and count hairs. This may involve pre-processing, image segmentation and count.
    You may look at our Media Library to see what tools are available in Premier: http://www.mediacy.com/resources/media 

    You can also post a sample image on the forum with detailed explanation what information you want to extract, so we have a better idea about your task.

    Yuri

  • mbatchelor
    mbatchelor
    2017-07-13-104743

    KTGERLOFF --

    I was unable to find images on the INTERNET that seemed to match the images that you are describing.  As a substitute I found a picture of DONUTS with slightly varying amounts of SPRINKLES.

    I have carried this picture through a process that analyzes the image and generates raw data that could be used for a SPRINKLE INDEX.

    I have done and attached some SCREEN CAPTURES that I believe illustrate the type of process that could be used to generate a HAIR INDEX for your leaves.

    I hope this information is helpful.

    -- MATT


    A = ORIGINAL IMAGE + SMART THRESHOLD + COUNT
    B = MASK OF A
    C = MASK OF HOLES from A using ROIs from B
    D = B - C


    E = A + MEASUREMENTS created using boundaries found with BRIGHT THRESHOLD on D


    F = SAME as E
    DATA TABLE on F shows HETEROGENEITY and INTENSITY STD DEV which could individually or combined be used for a SPRINKLE (HAIR) INDEX.
    F SORTED = F + COUNT SIZE RIBBON + IMAGE SECTION + SORT

    Based on this, the MOST SPRINKLED DONUT is the P1R3 and the LEAST SPRINKLED DONUT is P1R2 or P1R4.

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