📊File Size Limits

Uploaded art images must be large enough to have have quality resolution for each DAB, but not exceed file size limits for the server.

We'll cover this topic in two sections. First, we'll discuss file dimensions, or how large an image needs to be in order for a purchased DAB to have an acceptable resolution. Next, we'll discuss files size, or "how large is too large" when it comes to uploading files.

What is the minimum size my image needs to be

The minimum size an image should be is the size at which a certificate displays the image of a purchased DAB at at least 72dpi., which is the resolution of most computer screens.

For the purposes of these docs, we are talking about optimal size for a DAB Certificate to be displayed on-screen. We are assuming a screen resolution of 72dpi. Many newer computer monitors, such as retina or double density screens can actually display a much higher resolution, and if you wanted to print the certificate, the optimal resolution may be 150 or even 300 dpi. Because of the challenge of being able to support file uploads of the enormous size to support these higher resolutions, we will work initially with the 72dpi screen resolution at this point.

In order to calculate the size of the full image, we need to do some math based on how many DABs the image will be divided into. Below are two methods for calculating this.

I have the file, how many DABs can I divide it into

First, get the pixel dimensions of your image file. The resolution of the image does not matter.

The DAB is displayed at approximately 150px x 150px in the certificate.

To calculate how many DABs you can divide the image into, take the each side, and calculate how many times 150 can go into that length.

Example: Given a full-size image that is 6000px x 4500px.

• To calculate Columns, 6000 / 150 = 40

• To calculate Rows, 4500 / 150 = 30

Your image can be a maximum of 40 columns by 30 rows.

I know how many DABs I want, how large does my file need to be?

The DAB is displayed at approximately 150px x 150px in the certificate.

Take the number of rows and columns you would like to divide the image into, and multiple by 150

Example: You are setting up artwork that you would like to divide into 75 rows and 50 columns

• To calculate minimum image width: 75 x 150 = 11,250

• To calculate minimum image height: 50 x 150 = 7500

Your image must be a minimum of 11,250px wide and 7500px tall. (The resolution of the image does not matter)

When uploading an image in the Museum Application, the app some of this math for you. When you fractionalize the image, if it does not meet the minimum pixel size requirements, an alert will display at the top of the screen. You will still be able to continue creating the art, but this alert will inform you that there will be some image degradation of the DAB in the certificate.

This alert tells you that there will be some image degradation when generating the DAB for the certificate.

File size limits for uploaded art.

At the time of this writing, there are some limits to how large an image can be in order for it to be successfully uploaded to the server and processed into DABs. The exact limit is dependent on a number of factors, such as file size, file dimensions and image quality. We have done a number of tests, and found that this limit is somewhere around 10MB for an image, or roughly 10,000pixels wide or tall.

If you encounter issues when trying to upload images, try downsizing the image and re-uploading.

It's understood that this may cause some limitations around how many DABs an image can be divided into and still retain optimal image quality for the certificates. We can discuss further some of the options around upgrading server limitations or hosting solutions when the time comes.