What Image Type should I use in Filopto?
Depending on the possible use that you will make of the image you are storing in Filopto, the image type will have a big impact on performance and storage space required. Below is a small guide on the various image types and their possible use. As a quick guide consider using the PDF image format for storing documents, PNG for images you will need to edit, and JPEG for standard non-editable images.
Common Image File Types
Most image software will present you with save options such as .png, jpeg, .tiff, .gif or .pdf. Other more advanced image editors (such as Adobe Photoshop) offer additional formats like .svg, .psd, .psb, .bmp, .eps, .raw, to name a few. The main difference between all of these image formats comes down to two things: compression and compatibility.
File Type Name |
Description |
---|---|
JPEG/JPG (Joint Photographers' Expert Group) |
Most popular lossy image format. Allows uses to specify what level of compression they desire.
|
PNG (Portable Network Graphics) |
Best of lossless image formats. Widely supported across most applications. Allows you to include an alpha channel within the file.
|
BMP (BitMap) |
Would avoid if possible. They offer little to no compression which results in unnecessarily large files.
|
TIFF/TIF (Tagged Image File Format) |
Offers both compressed and uncompressed versions. Compressed are similar to PNG and uncompressed is similar to BMP. Commonly used to store low resolution fax images.
|
PDF (Portable Document Format) |
Most widely used document format. Great vector image format. Created by Adobe Inc.
|
EPS (Encapsulated PostScript) |
Most common vector image format. Standard format for print industry.
|
SVG (Scalable Vector Graphics)
|
SVG is an XML-based vector image format with support for interactivity and animation. |
GIF (Graphic Interchange Format) |
Lossless format that supports both animated and static images.
|
DICOM (Digital Imaging and Communications in Medicine) |
DICOM is a standard for handling, storing, printing, and transmitting information in medical imaging. Typically can be very large files. DICOM files can be exchanged between two entities that are capable of receiving image and patient data in DICOM format. Usually used in conjunction with the HL7 standard for data exchange protocol and equipment.
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Lossy vs. Lossless Compression
All of the files mentioned above fall into two main categories.
1) Lossy images, which can be described as image formats that do not store a perfect copy of the original image and thus have smaller file sizes.
2) And lossless images, which store an exact pixel-by-pixel representation of the image, but in doing so, require more space.
It’s not uncommon to come across both types when you are looking at photos on the web. The most popular lossless image formats are .tiff and .png. When working (editing) images saving your photos in a lossless format retains all the image quality. But if no editing is required a common lossy format such as .jpeg, allows you to choose the amount of compression, and therefore the file size and quality you want
Vector vs. Raster (bitmap) Images
Other common terms that you may have heard before in regards to image formats are vector art versus raster art. Raster art is made of a certain number of pixels and vector art is based on mathematical calculations. In other words, raster art cannot be scaled beyond 100% without losing quality and vector art does not use pixels and therefore is resolution-independent. Popular vector image formats include .eps (most common), .ai, .pdf, and .svg.
Proprietary Formats
A proprietary format refers to a file format created by a company, organization, or individual. These formats are typically controlled by a company and the restriction of their use is for their own benefit. This is in contrast to an open file format that can be published and used by anyone. Some examples include Photoshop’s .psd, or the National Electrical Manufacturers Association (NEMA) which holds the copyright to the DICOM format. It’s best to use these formats when you plan on editing the original project at a later time, since they maintain all of the original layers and editable properties. Proprietary formats usually have a larger file size and maintain full quality of the original image. Compatibility with third party image editors are where these formats fall short.
Alpha Channel
All colored image formats hold values for red, green and blue channels that make up the entire color spectrum, but certain formats offer the ability to retain an additional layer of transparency or “alpha channel” that is built into the file. The main benefit is that the format allows you to add graphics on top of other graphics without having a “white box” around it. The most popular image format that holds an alpha channel is the .png format.