R.J. O'Callaghan

1.0k total citations · 1 hit paper
5 papers, 810 citations indexed

About

R.J. O'Callaghan is a scholar working on Computer Vision and Pattern Recognition, Media Technology and Infectious Diseases. According to data from OpenAlex, R.J. O'Callaghan has authored 5 papers receiving a total of 810 indexed citations (citations by other indexed papers that have themselves been cited), including 5 papers in Computer Vision and Pattern Recognition, 3 papers in Media Technology and 0 papers in Infectious Diseases. Recurrent topics in R.J. O'Callaghan's work include Remote-Sensing Image Classification (3 papers), Advanced Image and Video Retrieval Techniques (2 papers) and Image Retrieval and Classification Techniques (2 papers). R.J. O'Callaghan is often cited by papers focused on Remote-Sensing Image Classification (3 papers), Advanced Image and Video Retrieval Techniques (2 papers) and Image Retrieval and Classification Techniques (2 papers). R.J. O'Callaghan collaborates with scholars based in United Kingdom and Japan. R.J. O'Callaghan's co-authors include David Bull, Nishan Canagarajah, J. Lewis, S.G. Nikolov, D.R. Bull, Daniel Heesch and Stefan Rüger and has published in prestigious journals such as IEEE Transactions on Image Processing, Information Fusion and Text REtrieval Conference.

In The Last Decade

R.J. O'Callaghan

4 papers receiving 775 citations

Hit Papers

align trajectories

What are hit papers?

Hit papers significantly outperform the citation benchmark for their cohort. A paper qualifies if it has ≥500 total citations, achieves ≥1.5× the top-1% citation threshold for papers in the same subfield and year (this is the minimum needed to enter the top 1%, not the average within it), or reaches the top citation threshold in at least one of its specific research topics.

Pixel- and region-based image fusion with complex wavelets

2005 676 citations J. Lewis, R.J. O'Callaghan et al. Information Fusion profile →

Peers — A (Enhanced Table)

Peers by citation overlap · career bar shows stage (early→late) cites · hero ref

Name	h						Papers	Cites
R.J. O'Callaghan United Kingdom	4	696	605	157	83	28	5	810
J. Lewis United Kingdom	9	782 1.1×	581 1.0×	218 1.4×	86 1.0×	26 0.9×	12	833
Zhuliang Le China	10	896 1.3×	780 1.3×	155 1.0×	124 1.5×	31 1.1×	13	1.0k
David Capel United Kingdom	9	374 0.5×	815 1.3×	139 0.9×	20 0.2×	19 0.7×	10	880
Artur Łoza United Kingdom	9	292 0.4×	434 0.7×	92 0.6×	40 0.5×	13 0.5×	22	537
Yan Pingfan China	3	1.2k 1.7×	871 1.4×	348 2.2×	135 1.6×	53 1.9×	4	1.3k
Yue Que China	14	564 0.8×	525 0.9×	65 0.4×	118 1.4×	45 1.6×	22	704
Mauricio Delbracio United States	10	258 0.4×	609 1.0×	51 0.3×	26 0.3×	18 0.6×	25	696
Bryan Chou United States	15	205 0.3×	248 0.4×	79 0.5×	44 0.5×	15 0.5×	31	423
Mona Mahmoudi United States	4	226 0.3×	507 0.8×	42 0.3×	35 0.4×	29 1.0×	6	622

Countries citing papers authored by R.J. O'Callaghan

Since Specialization

Citations

This map shows the geographic impact of R.J. O'Callaghan's research. It shows the number of citations coming from papers published by authors working in each country. You can also color the map by specialization and compare the number of citations received by R.J. O'Callaghan with the expected number of citations based on a country's size and research output (numbers larger than one mean the country cites R.J. O'Callaghan more than expected).

Fields of papers citing papers by R.J. O'Callaghan

Since Specialization

Physical SciencesHealth SciencesLife SciencesSocial Sciences

This network shows the impact of papers produced by R.J. O'Callaghan. Nodes represent research fields, and links connect fields that are likely to share authors. Colored nodes show fields that tend to cite the papers produced by R.J. O'Callaghan. The network helps show where R.J. O'Callaghan may publish in the future.

Co-authorship network of co-authors of R.J. O'Callaghan

This figure shows the co-authorship network connecting the top 25 collaborators of R.J. O'Callaghan. A scholar is included among the top collaborators of R.J. O'Callaghan based on the total number of citations received by their joint publications. Widths of edges represent the number of papers authors have co-authored together. Node borders signify the number of papers an author published with R.J. O'Callaghan. R.J. O'Callaghan is excluded from the visualization to improve readability, since they are connected to all nodes in the network.

All Works

Sort: Min cites: Since: Top N: Style:

5 of 5 papers shown

1.

O'Callaghan, R.J., et al.. (2007). Robust Change-Detection by Normalised Gradient-Correlation. 2. 1–8. 8 indexed citations

2.

Lewis, J., R.J. O'Callaghan, S.G. Nikolov, David Bull, & Nishan Canagarajah. (2005). Pixel- and region-based image fusion with complex wavelets. Information Fusion. 8(2). 119–130. 676 indexed citations breakdown →

3.

O'Callaghan, R.J. & D.R. Bull. (2004). Combined morphological-spectral unsupervised image segmentation. IEEE Transactions on Image Processing. 14(1). 49–62. 109 indexed citations

4.

Heesch, Daniel, et al.. (2002). Video Retrieval Using Global Features in Keyframes.. Text REtrieval Conference. 17 indexed citations

5.

O'Callaghan, R.J. & David Bull. (2002). Improved illumination-invariant descriptors for robust colour object recognition. IEEE International Conference on Acoustics Speech and Signal Processing. IV–3393.

Rankless uses publication and citation data sourced from OpenAlex, an open and comprehensive bibliographic database. While OpenAlex provides broad and valuable coverage of the global research landscape, it—like all bibliographic datasets—has inherent limitations. These include incomplete records, variations in author disambiguation, differences in journal indexing, and delays in data updates. As a result, some metrics and network relationships displayed in Rankless may not fully capture the entirety of a scholar's output or impact.

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