Standard High Precision Pictures: SHIPP

Along with the recent rapid penetration of personal computer, internet, digital camera, etc., full color images have become widely handled in digital form by various classes of users. In such a trend, technologies for color management system (CMS), printing, hardcopy output, image transmission, image compression, etc. are highlighted, and their refinements are on way to achieve higher image qualities. In the research activities in image technologies, the significance of high precision standard pictures is self-evident as they facilitate the evaluation of image processing algorithm, the accurate comparison of image output devices, etc. In April 1997, the activity of the Committee for Standard High Precision Pictures (Note 1) has resulted in the preparation of high resolution standard pictures characterized by that they are expressed by 16-bit XYZ data as well as 8-bit CIELAB data and Calibrated RGB data. The set of pictures named SHIPP consists of four full color natural scenes and a computer-generated chart, each expressed in three color spaces, i.e., XYZ, CIELAB, and Calibrated RGB. A detailed description of the last color space will be given later. The image data are formated ac cording to TIFF6.0 and recorded in a CD-ROM. Objectives and Background An example of standard color image data is given by ISO/ JIS-SCID (Standard Color Image Data (Note 2)). This is the first standard in the form of digital data commonly applicable to any output devices, and is now widely used in the technical fields of printing, hardcopy, image transmission and compression, etc. However, there are a few problems with SCID. Since it originated in the commercial printing industries, its image data is described in terms of the dot coverages in CMYK, which makes it difficult to accurately define colors when the data are to be used in image media other than conventional printing. Moreover, the data depth is limited to 8-bits/channel, thus sometimes causing noticeable quantization errors during various types of image processing. In order to solve these problems, the Committee for Standard High Precision Pictures started its activity to prepare a set of standard pictures with the following characteristics: 1). Device-independent XYZ/CIELAB values, 2). Image data of 2-bytes/channel, and 3). Image resolution of 4096 × 3072. The activity resulted in the development of a set of full color pictures named SHIPP satisfying the above aims in April 1997. SHIPP is expected to meet well the today’s requirements in the various technical fields such as the color gamut evaluation of imaging systems, the image quality evaluation of image output devices, the estimation of the degree of quality deterioration accompanied by image data compression, etc. Full Color Natural Scenes and Color Chart Comprising SHIPP Table 1 depicts the specifications of the image data for full color natural scenes and for the color chart composing SHIPP. In choosing these scenes, the 8 scenes of SCID were referred to from the viewpoint of significant attributes for Table 1. Specifications of SHIPP No. Nickname Pixels Color Space Data Volume Main Subjects Evaluation Objects (width × height) (mbytes) XYZ 75.5 Tone reproduction P1 Bride 3072 × 4096 CIELAB/ 37.7 Close-up portrait of flesh Calibrated RGB XYZ 75.5 Fine, regular Image processing P2 Harbor 4096 × 3072 CIELAB/ 37.7 structures technique Calibrated RGB XYZ 75.5 Highly saturated Color P3 Wool 4096 × 3072 CIELAB/ 37.7 colored products reproduction Calibrated RGB XYZ 75.5 Lustrous metal Reproduction P4 Bottles 3072 × 4096 CIELAB/ 37.7 products of gray Calibrated RGB XYZ 21.8 Color C1 Chart 2736 × 1332 CIELAB/ 10.9 Color patches reproduction Calibrated RGB