brightness {nandb}

Calculate brightness from image series.

Description

Given a time stack of images, brightness() performs a calculation of the brightness for each pixel.

Usage

brightness(
  img,
  def,
  thresh = NULL,
  detrend = FALSE,
  quick = FALSE,
  filt = NULL,
  s = 1,
  offset = 0,
  readout_noise = 0,
  parallel = FALSE
)

Arguments

img

A 4-dimensional array in the style of an ijtiff_img (indexed by img[y, x, channel, frame]) or a 3-dimensional array which is a single channel of an ijtiff_img (indexed by img[y, x, frame]).

def

A character. Which definition of brightness do you want to use, "B" or "epsilon"?

thresh

The threshold or thresholding method (see autothresholdr::mean_stack_thresh()) to use on the image prior to detrending and brightness calculations.

detrend

Detrend your data with detrendr::img_detrend_rh(). This is the best known detrending method for brightness analysis. For more fine-grained control over your detrending, use the detrendr package. If there are many channels, this may be specified as a vector, one element for each channel.

quick

If FALSE (the default), the swap finding routine is run several times to get a consensus for the best parameter. If TRUE, the swap finding routine is run only once.

filt

Do you want to smooth (filt = 'mean') or median (filt = 'median') filter the number image using smooth_filter() or median_filter() respectively? If selected, these are invoked here with a filter radius of 1 (with corners included, so each median is the median of 9 elements) and with the option na_count = TRUE. If you want to smooth/median filter the number image in a different way, first calculate the numbers without filtering (filt = NULL) using this function and then perform your desired filtering routine on the result. If there are many channels, this may be specified as a vector, one element for each channel.

s

A positive number. The S-factor of microscope acquisition.

offset

Microscope acquisition parameters. See reference Dalal et al.

readout_noise

Microscope acquisition parameters. See reference Dalal et al.

parallel

Would you like to use multiple cores to speed up this function? If so, set the number of cores here, or to use all available cores, use parallel = TRUE.

Value

A matrix, the brightness image.

References

Digman MA, Dalal R, Horwitz AF, Gratton E. Mapping the Number of Molecules and Brightness in the Laser Scanning Microscope. Biophysical Journal. 2008;94(6):2320-2332. doi: 10.1529/biophysj.107.114645.

Dalal, RB, Digman, MA, Horwitz, AF, Vetri, V, Gratton, E (2008). Determination of particle number and brightness using a laser scanning confocal microscope operating in the analog mode. Microsc. Res. Tech., 71, 1:69-81. doi: 10.1002/jemt.20526.

Examples

img <- ijtiff::read_tif(system.file("extdata", "50.tif", package = "nandb"))
ijtiff::display(img[, , 1, 1])
b <- brightness(img, "e", thresh = "Huang")
b <- brightness(img, "B", thresh = "tri")