In this section you will get an overview of the difference between raw images (e.g., 8- or 16-bit images in czi- or lif-format) and processed images (e.g., RGB-images in png- or tif-format). In general, the images you take at the microscope should be exported as raw images (czi, lif, ...) and not as processed images (png, jpeg, ...). The raw images contain important information like original pixel intensites and meta data (like pixel size, objective magnification, used lasers, and gain) and can be used for quantitative analysis and to be processed (e.g., color adjustment and insertion of a scale bar) and exported as figures (e.g. as RGB-images in png-format).
An image is a two-dimensional representation of visual information. It is an array of pixels, where each pixel represents a specific color and intensity. In digital images, the pixels are stored as numerical values in a computer-readable format.
Images have several properties that describe their characteristics, including:
- Resolution: The number of pixels per inch or per centimeter.
- Bit depth: The number of bits used to represent each pixel. This determines the number of different shades of color that can be represented.
- Color model: The system used to represent colors in the image, such as RGB (red, green, blue) or HSL (hue, saturation, lightness).
- Compression: The method used to reduce the size of the image file, if any.
Images can contain different types of information, including:
- Visual information such as color, texture, and shape of objects within the image.
- Metadata such as the date and time the image was captured, camera settings, and geo-location.
There are many different file formats for images, each with its own strengths and weaknesses. Some of the most common image file formats include:
- JPEG: A lossy format that is widely used for photographic images.
- PNG: A lossless format that supports transparency and is often used for graphics.
- GIF: An older format that supports animation and a limited number of colors.
- BMP: An uncompressed format that is widely supported, but can produce large files.
- TIFF: A flexible format that can be either lossless or lossy and supports multiple images in a single file
Some other formats are DICOM, NIfTI, HDF5 for medical imaging, OME-TIFF for microscopy and bioimage analysis .
Additional information can be found here:
