The ability to understand and critically analyze the composition, content, and context of digital images, as opposed to original objects, is crucial to understanding and interpreting digital images. This process includes closely examining what you see in a particular image and asking questions based on what you see to establish historical and cultural context.
The Yale University Art Gallery has many online features on What is Art and Why Does it Matter? offering diverse perspectives on their incredible collections. Here are some additional resources for learning about reading images and visual literacy.
Reliability
Digital images should be evaluated with the same scrutiny as web sites, online journal articles, and any other information you find online.
Source
Cultural institutions, colleges, universities and some commercial organizations often provide the best quality images with the most accurate information (metadata). Always check the site where you found an image for copyright and/or licensing information. Please remember, images found via Google Images are not owned by Google. Always trace images back to the original URL in the Google Image search and ultimately back to the owner and/or exhibitor.
Technical Specifications
Resolution
Resolution largely dictates the clarity and quality of the image. Digital images are made up of hundreds of small dots called pixels (picture elements). The more pixels there are per inch (ppi) the higher the resolution and the better the image quality. High quality resolution for printing is 300 ppi, but 72 ppi is appropriate for display on a computer monitor. When downloading, an image 1024 pixels along the long edge is optimal for reproduction.
Format
JPEG (.jpg): Many images are stored as JPEG files because this format allows files to be compressed to take up less space. Because JPEG files are small, they are easily transported (email, flashdrives, etc).
GIF (Graphics Interchange Format, .gif): Another popular file type found on the web. Gif images are widely used for graphics.
TIFF (Tagged Image File Format, .tif): saves an uncompressed digital reproduction. Therefore, it is recommended you originally save high-quality TIFFs and then create JPEGs for general use.
BMP: uncompressed proprietary Microsoft format.
Other formats include, but are not limited to PSD (Photo Shop Document), SVG, and RAW. Image software tends to allow conversion of one format to another.
