Automatic Photo Enhancement Server (HIPIE 2)

HIPIE 2 is an internal name for the HP Smartstream Photo Enhancement Server, robust, scalable, and automatic photo image enhancement software, customized for photo specialty workflows fulfilled using Indigo presses. It is designed for 24/7 operation, without human intervention, and is part of HP Indigo's Smartstream workflow offering. The codename HIPIE stands for the original "HP Indigo Photo Image Enhancement" name, with HIPIE 2 being its second version.

With the advent of digital press, photo specialty prints emerged as an important category for commercial print. This includes photobooks, customized posters, and calendars. These applications include consumer photographs, which are not as optimized for print as those professional photographs used in traditional jobs. Consumer pictures are often too dark or too bright, not colorful enough, and/or not sharp enough, for instance. As a result, Print Service Providers that fulfill photo specialty workflows have the need to improve image quality in addition to keeping a high print quality.

HIPIE 2 is an automatic image enhancement package, which works as part of a commercial print environment, enhancing each incoming photograph in a fast and reliable way. It improves the visual appearance of the photos as they are printed in photo specialty products, without human intervention. It is commercialized by HP Indigo as part of their photo quality offering, and as part of the HP Smartstream workflow offering, under the name "HP Smartstream Photo Enhancement Server".

HIPIE 2's image enhancement is state-of-the-art. We have introduced innovative enhancements, such as 3D boosting and face make-up. Image analysis modules determine the amount and type of enhancements needed for each individual photograph. The user is able to apply the following image processing tasks. All these tasks are completely automatic, but their strengths can be influenced by the user controls.

• Sharpening Each input image is sharpened as needed, so that it appears at the right sharpness in print.
• Noise reduction Noise is estimated, and then reduced, without damaging texture or fine details in the image.
• 3D boosting This is a novel feature, whereby shadings are enhanced so to give an impression of increased depth to the objects in the image (see Fig. 2).
• Contrast enhancement Low-contrasted images have their effective dynamic-range stretched; this includes lowexposure images, which are brightened (see Fig. 3).
• Shadow detailing HIPIE 2 detects the low-exposed regions of the image, and brightens them, without demaging the well-exposed regions of the image (see Fig. 4).
• Face make-up Another novel feature, this makes sure that skin on faces are smoothed, as if the subject applied makeup, reducing the visibility of wrinkles and minor blemishes.
• Chroma boosting HIPIE 2 enhances overall image chromaticity.
• JPEG artifact reduction Blocking and ringing artifacts, typical from strong JPEG compression, are reduced.
• Face color correction Skin color is analyzed and corrected for photos with a color cast.
• Resolution Enhancement If the image resolution is too low, compared to the target print size, then the resolution is doubled by a smart interpolation algorithm in order to avoid jagginess or pixelization on edges.
• Red-eye removal Optionally, HIPIE contains a module for automatically detecting and removing red-eye effects.