A digital frame (or digital photo frame) is an electronic device that reproduces the appearance of a frame, to display one or more photos from a digital source without the aid of a microcomputer.
They usually rely on LCD, TFT, QLED and e-ink technology for display. The surface, matt or glossy finish, with a diagonal of 7 inches to 85 inches is in 4/3 format (the definition of the panel can reach from 1024 x 768 pixels to 4K resolution). If the screen does not have a format homothetic to the photo (of the same ratio as the photo), it may display it distorted or appear with black bars.
Some digital frames have internal memory (for example, a capacity of 256 GB can store several thousand photos), which can be loaded from USB connectivity (connection to a USB key or external hard drive, or a microcomputer);
or a memory card of different formats (SD and SDHC, MS, MS Pro, CF, MMC, SM, xD, etc.); or via wireless technologies such as Bluetooth or Wi-Fi or over the internet. Photos of JPEG, BMP, TIFF and RAW formats can be played. Over time, these devices are enriched with new features, such as sound accompaniment (audio files in MP3, WAV, and WMA format) or playback of video sequences (MPEG, AVI files).
DIY Options of Digital Photo Frame
With the advent of Arduino-compatible microcontrollers and Raspberry Pi, 3D printing and relatively cheaper TFT and e-ink displays, there are numerous projects all over the internet to create own digital photo frame at a fraction of the cost. While the advantage of this method is budget saving, usually there is no warranty coverage or repairability.
For example, this project gives you the required code and instructions to create a digital photo frame with 4.3 inch E-ink display module and Arduino mini pro. The image in this article is used from that project.