Image Output and Saving
Choosing a format
Output begins with format choice. JPEG uses lossy compression, suits photographs, and cannot store transparency. PNG is lossless, supports transparency and sharp graphics, and is common for screenshots and web images. GIF is limited to 256 colours but supports simple animation and binary transparency. TIFF is lossless and favoured for print and archiving, though files are large. BMP is typically uncompressed and inefficient. SVG stores vector graphics. Camera RAW needs processing before it becomes a standard output file.
Saving, exporting and printing
Save updates the working file in its current format; Save As creates a new file or format; Export usually produces a copy for a specific destination, sometimes with optimisation. Compression settings trade quality against file size. Metadata can be preserved or stripped, and an ICC profile helps consistent colour. For print, set paper size, orientation, scaling, and colour management; for web, resize to sensible pixel dimensions, convert to sRGB, and check file size.
Traps: repeatedly resaving JPEGs; expecting a renamed file to change format; assuming a dpi number changes pixel dimensions; using GIF for photographic gradients.
Worked example: a photo for email should be resized to roughly 1600 pixels on the long edge, converted to sRGB, saved as JPEG at moderate-to-high quality, and checked for size. Rule of thumb: choose format by content and destination - photographs to JPEG, transparency or sharp graphics to PNG, print masters to TIFF.