Data sources and formats
Browse image files are generally small in size but very large in number. These images are typically reduced-resolution versions of the original raw dataset to provide a quick visual review prior to obtaining the full-resolution data. Browse imagery is typically stored as 8-bit, three-band JPEG files. Some browse imagery may be stored as TIFF files with JPEG compression (recommended) or use other formats such as PNG files. Using reduced-resolution JPEG-format images makes it easy to access the imagery in a web browser. The JPEG-format files are not as optimum for serving imagery as TIFF files with JPEG compression since JPEG files need to be decompressed completely (beginning to end). When using small browse images, it is generally not necessary to convert the images. If using full-resolution browse imagery or browse images with more than about 2,000 columns or rows, it is beneficial to convert the imagery to TIFF files for better performance. (Use JPEG_YCBCR compression for natural color and JPEG for panchromatic.)
For users seeking to download sample data, samples and sources of browse imagery can be found at the following websites:
Dataset Name | Dataset Source |
|---|---|
Landsat Look | |
Geoeye | |
Digital Globe |