Overview
exImage provides an intuitive pictographic view of expression data across a diverge range of PlantGenIE datasets.

Basic Usage
Users can either enter a gene ID in the input text area (and hit the “GO” button) or create a gene list which then will appear as an interactive list in the tool. exImage will shade the samples according to expression levels across multiple samples using either absolute or relative values. Relative values displays expression relative to the mean expression across all samples. The current view can be exported in various vector formats including publication ready PDFs or as expression values. The ‘Take a tour’ feature will provide a brief introduction to the basic functionalities in exImage.

Data
exImage uses TPM (Transcripts Per Kilobase Million) values for absolute expression, and no unit for the relative values. Absolute expression values were generated by aligning RNA-Seq reads to the reference genome and gene annotation with aligned read numbers then used to calculate TPM values.

Implementation
exImage was developed using PHP, Javascript, d3js, rsvg-convert, imagemacgick, librvg and batik. exImage uses a MySQL database as a backend data source. exImage was inspired by the eFP resource.