Tag Archives: Peer-reviewed research

How to maintain high-quality images for publication


How to ensure your photos, graphs and illustrations are of suitable quality for publication

Digital images are stored in different formats, depending upon the software. Common examples include TIFF, JPEG and EPS. Before preparing figures for the web or for print, it is vital to ensure that the appropriate resolution is used.

Resolution describes the number of pixels within an image and image quality increases with resolution. A pixel is the smallest unit of digital information that forms an image. Resolution can be expressed as the number of pixels per dimension (e.g. 1200 pixels wide by 750 pixels high) or as the number of pixels within a specified area (pixels per inch or ppi). An image that has a resolution of 300ppi and is 4 x 2.5 inches in size, will be 1200 pixels wide (4 x 300) = and 750 pixels high (2.5 x 300). In general, the more pixels you have per unit area, the more detailed the image will be and the larger the file size. Some software (such as Photoshop) allows you to change the units to pixels per centimetre; however, the publishing standard is usually ppi.

The resolution of an image for viewing on a monitor is described in ppi, whereas the term dots per inch (dpi)describes the resolution of a printed image, as printers print dots and not pixels. The terms are used interchangeably but for most purposes, ppi and dpi are essentially the same thing to describe resolution. To view an image on the accepted resolution is 72ppi as most LCD monitors display 67-130ppi. When submitting figures for publication, 300 ppi is the generally accepted resolution for print images.

    High quality (300ppi)                                                                      Low quality (50ppi)

If your image needs to be 300ppi, then you need to consider the size of your image in the final printed form and the number of pixels in your total image. A photo that will be 4 x 2.5 inches when printed will need at least 1200 x 750 pixels to achieve the desired print-quality resolution of 300 ppi. If you have fewer pixels, then the quality of the image (i.e. the resolution) will be reduced. You can also quickly check whether the resolution is sufficient by zooming your image to 400% and if it is blurry (pixelated), then the image may not reproduce well when printed. For more information on image resolution, and another way to check if the resolution of your image is appropriate, see https://www.thecanvasprints.co.uk/image-resolution-for-printing. ​

When re-sizing an image, some software programmes automatically change the size of the image without changing the number of pixels. For example, if you re-size a 1200 x 750 pixel image from 4 x 2.5 inches to a 12 x 7.5 inches the number of pixels will remain the same but the resolution will drop from 300ppi to 100ppi . The larger image will look OK on the screen, but the image quality will be poor if it is printed. Whatever image size you require, ensure the final version is at the desired resolution.

Additional terminology

Colour space is the way colour information is stored in a file. Grayscale refers to black and white (and grey!) images which use a single colour channel. RGB is a commonly-used colour space that divides colours into 3 channels: Red, Green and Blue. RGB is used by computers and digital devices and is commonly used by publishers who want to make sure their documents are properly displayed on their reader’s devices. CMYK is a four channel colour space (cyan, magenta, yellow and black) commonly used during the printing process. An RGB image might need to be converted to CMYK if it will be printed. Some publishers will do the conversion themselves, so you need to be aware that the colour of RGB images may look different when converted to CMYK.

Re-sampling changes the number of pixels in an image. Re-sampling is different to re-sizing. Down-sampling removes pixels and creates a smaller image, whereas up-sampling adds pixels using algorithms. Because re-sampling adds or removes pixels, a loss of image quality could result. This could be particularly important if you are presenting images that are taken from a microscope; it is imperative that re-sampling does not change the specific features of the data within the micrograph. As a general rule, create your images at the highest resolution possible to avoid the need to re-sample. However, re-sampling may sometimes be necessary; for example, when converting a very high-resolution image to a small size (2 x 2 inches). Always keep original files and ensure that the re-sampling process only happens towards the end of the figure creation process, so that you can go back to the original image if needed.

​Image compression: Some file types (e.g. JPG) compress the pixels in the image to reduce file size. Be aware that different compression methods can affect image quality. Pay attention to the publisher’s requirements for compression and whether your software compresses by default.

Raster vs vector images: Raster images use raster data that is stored as pixels, for example, digital photographs. Because raster images use pixels, the quality is highly dependent on resolution. Vector images use vector data comprised of lines and curves, for example, line graphs. Because vector images do not use pixels, they can be re-sized to a very large size without becoming pixelated and losing quality. If you are publishing images that are line graphs only, consider using vector format files such as EPS. However, if you are assembling a line graph into a larger figure that includes digital images, the entire figure will become rasterised at some point; meaning that your vector image will become a raster image and need high resolution.

Additional reading on this topic

Introduction to Digital Resolution.
Image resolution and print quality.
How to create publication-quality figures.
The difference between image re-sizing and re-sampling.
Science: preparing your art and figures.

© Dr Liza O’Donnell and Dr Marina Hurley  2019 www.writingclearscience.com.au

Any suggestions or comments please email info@writingclearscience.com.au 

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How to choose the right journal to publish your paper

Choosing the right journal is a crucial step in getting your paper successfully published. Where you publish is also important when establishing your career as a researcher and may improve your ability to attract funding. Choosing the right journal is an important part of the planning process when drafting your paper. Ideally, you should decide what journal you will submit to before you start writing, as each journal will have unique requirements and will target different audiences.

1. Create a draft list of journal titles that appear suitable at first glance

Based upon your knowledge, advice from colleagues and word-of-mouth, create a draft list of 20-40 journal titles that appear suitable at first glance. You can also use search engines (e.g. ‘marine biology journals’) and journal finder tools and databases (e.g. Scopus). Also look in the reference lists of the papers that you read.  

2. Define your publishing objectives and preferred journal attributes

In addition to simply wanting your paper to be published, you need to have clear objectives about how and where you want your work published. Determining how different journals can meet your objectives will help you decide what journal to choose. Having clear publishing objectives is also important if you are co-authoring a document.

The following is a list of journal attributes that should be considered when working out your objectives:

Does the journal meet your institutions’ or funding body’s guidelines?   

Different universities, departments and other organisational will have guidelines and criteria for journal selection. For example, the Excellence in Research for Australia (ERA) is Australia’s national research evaluation framework and stipulate that research output must satisfy certain criteria, including the type of journal.

Does your study subject and publication type meet the journal’s Aim and Scope?

The journal’s Aims and Scope gives an overview of what subject or topics they publish; for example, the Journal of Cell Science states it is “…committed to publishing the full range of topics in cell biology.” The journal’s Aims and Scope often outlines what types of papers they publish and their peer review policy. Other crucial information (e.g. page limits) will also be found in the Instructions to Authors.


Consider the journal’s readership and target audience 

Does the journal’s readership and target audience match the target audience of your paper? For example, if you have a multi-disciplinary project or topic, you might want to choose a multi-disciplinary journal (for example PLOS One).

What is the journals’ Impact Factor?

The impact factor of a journal is a high profile and controversial measure used to rank, evaluate and compare journals and is published in the Journal Citation Reports (JCR) by Clarivate Analytics. Clarivate Analytics defines impact factor as a “a measure of the frequency with which the “average article” in a journal has been cited in a particular year or period. The annual JCR impact factor is a ratio between citations and recent citable items published.”

Is the journal indexed in well-known databases?

Indexing refers to whether a journal is listed in databases and search engines well known within your discipline. If your journal of choice is indexed by a well-known database (for example Web of Science or PubMed), once your paper is published, both your journal and paper will be found within this database. Some databases only include abstracts, some include the entire paper and the citation index. Read more about indexing here.

Do you agree with the journals peer-review policy?

This information should be listed on their website, often under the Aims and Scope section. For example, the journal Trials uses an open review system.

How long does the journal take to publish your paper?

The time taken to review your document and notify you of acceptance or rejection will vary between journals and can be a source of frustration. Knowledge of the publishing process will help you determine when to expect to receive a response.  ‘The production process’ by Wiley clearly outlines the steps taken with their journals. Some journals take longer to release your paper after acceptance than others. The Journal of Medical Internet Research estimates it takes them from 4-6 weeks.

Where do your peers publish?

Your paper needs to be seen by your peers if it has any chance of being read and cited. Therefore, it should be published in the journals that they are likely to read. For example, if I were an active researcher in Australia, I would consider publishing in Austral Ecology as it is well known and highly regarded.

Check the journal’s reputation

Only publish your paper in reputable journals. Early-career researchers might be not fully aware of fake or predatory journals that pretend to have a good reputation, accept your paper with minimal or no review and then charge you for submission. If you send a paper to a predatory journal, you might never hear from them again or see your paper anywhere in print. Think. Check. Submit is a system designed to help authors to identify trusted journals, including a check list to assess your chosen journals. 

Does the journal charge fees for publishing your paper?

Many journals not only charge for subscription and purchase of papers they publish, they also charge authors fees for publishing their papers after they have been accepted for publication.  Remember that your institution may already cover these charges. Read ‘Understanding Submission and Publication Fees’ for further background.  Even if a journal is open source, you many still need to pay paper charges. Read this article for further explanation.

3. Create a short-list of journals that meet your objectives

Create a short-list of the journals that meet your objectives. Perhaps also compile a spreadsheet of your short-listed journals to easily compare different attributes. This spreadsheet can be updated when preparing your next publication.

4. Once you have chosen the journal for submission, thoroughly review their requirements

Read your chosen journal’s website meticulously, especially the Aims and Scope and the Instructions of Authors. A common reason for paper rejection or request for resubmission is that the author has not comprehensively followed these instructions. Without thorough investigation, you may overlook important aspects that will prevent you from getting your paper published and it is better to find this out before you go through the process of writing, formatting and submitting your paper.

Finally...

Don’t forget that if you are unsure about anything, contact the editor. Some journals have information about pre-submission enquires on their websites, while most will have online articles and guides to help you understand their requirements.

© Dr Marina Hurley 2019 www.writingclearscience.com.au

Any suggestions or comments please email info@writingclearscience.com.au 

Find out more about our new online course..

How to be an Efficient Writer

Do you struggle with the amount of time it takes to write? When writing about science it is easy to drift off from your key topic when researching, planning and writing. 
Dr Marina Hurley shows you how to stay on track and be more efficient at each stage of the writing process. Irrespective of your topic, background, level of writing experience or document type, you can implement these steps to work on your first draft or rework a current draft.

Next course opens 26th September 2019

SUBSCRIBE to the Writing Clear Science Newsletter to keep informed about our latest blogs and writing workshops.

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