| ImageJ | |
|---|---|
 | |
 Screenshot of ImageJ | |
| Developer | Wayne Rasband (retired fromNIH) |
| Stable release | 1.54r[1]  / 25 September 2025 |
| Operating system | Any (Java-based) |
| Type | Image processing |
| License | Public Domain,BSD-2 |
| Website | imagej |
| Repository | |
ImageJ is aJava-basedimage processing program developed at theNational Institutes of Health and the Laboratory for Optical and Computational Instrumentation (LOCI, University of Wisconsin).[2][3] Its first version, ImageJ 1.x, is developed in thepublic domain, while ImageJ2 and the related projectsSciJava,ImgLib2, andSCIFIO are licensed with a permissiveBSD-2 license.[4] ImageJ was designed with anopen architecture that providesextensibility via Javaplugins and recordable macros.[5] Custom acquisition, analysis and processing plugins can be developed using ImageJ's built-in editor and a Java compiler. User-written plugins make it possible to solve many image processing and analysis problems, from three-dimensional live-cell imaging[6] toradiological image processing,[7] multiple imaging system data comparisons[8] to automatedhematology systems.[9] ImageJ's plugin architecture and built-in development environment has made it a popular platform for teaching image processing.[10][11]
ImageJ can be run as an onlineapplet, a downloadable application, or on any computer with a Java 5 or latervirtual machine. Downloadable distributions are available forMicrosoft Windows, theclassic Mac OS,macOS,Linux, and theSharp Zaurus PDA. Thesource code for ImageJ is freely available.[12]
The project developer, Wayne Rasband, retired from the Research Services Branch of theNIH'sNational Institute of Mental Health in 2010, but continues to develop the software.
ImageJ can display, edit, analyze, process, save, and print8-bit color and grayscale,16-bit integer, and32-bit floating point images. It can read manyimage file formats, includingTIFF,PNG,GIF,JPEG,BMP,DICOM, andFITS, as well as raw formats. ImageJ supports imagestacks, a series of images that share a single window, and it ismultithreaded, so time-consuming operations can be performed in parallel on multi-CPU hardware. ImageJ can calculate area and pixel value statistics of user-defined selections and intensity-thresholded objects. It can measure distances and angles. It can create densityhistograms andline profile plots. It supports standard image processing functions such as logical and arithmetical operations between images, contrast manipulation,convolution,Fourier analysis, sharpening,smoothing, edge detection, andmedian filtering. It doesgeometric transformations such asscaling, rotation, and flips. The program supports any number of images simultaneously, limited only by available memory.
Before the release of ImageJ in 1997, a similar freeware image analysis program known asNIH Image had been developed inObject Pascal forMacintosh computers running pre-OS X operating systems. Further development of this code continues in the form ofImage SXM, a variant tailored for physical research of scanning microscope images. AWindows version –ported by Scion Corporation (now defunct), so-calledScion Image for Windows – was also developed. Both versions are still available but – in contrast to NIH Image – closed-source.[13]
On January 25, 2017, AstroImageJ (AIJ) was published by Karen Collins, John Kielkopf, Keivan Stassun, and Frederic Hessman. AIJ built upon the ImageJ processing pipeline, streamlining the software to excel at time-series differential photometry, light curve detrending and fitting, and ultra-precise light curve plotting. AIJ reads and write FITS files, generates master frames, and handles dark, bias, and flat-field subtraction all within the software. AIJ is used formulti-aperture differential photometry andexoplanettransit modeling, with built-in support for modifying aperture and annulus radii, choosing target and comparison objects simply by clicking, adjusting transit priors, and exporting data as a FITS and/or XML file.[14]
