Beck Graphics Bitmap (BGB) File Format Specification

Transcription

1 Beck Graphics Bitmap (BGB) File Format Specification Copyright Beck IPC GmbH Page 1 of 5

2 TABLE OF CONTENTS 1 INTRODUCTION FILE HEADER PIXEL DATA EXAMPLE HISTORY... 4 Copyright Beck IPC GmbH Page 2 of 5

3 1 Introduction The Beck Graphics Bitmap (BGB) file format is a bitmap file format optimised for usage in conjunction with Beck IPC s graphics controllers. The BGB file format uses the colour format also used internally by the graphics controllers and can thus be loaded and processed faster than other graphics file formats. The file extension of Beck Graphics Bitmap files is.bgb. Little endian data format is used. 2 File header Each BGB file starts with a file header. Table 1 describes the various fields of the header, their offset and size. Offset Size [bytes] Name Description 0x00 2 signature Signature indicating a Beck graphics file; must be set to 0x534A 0x02 1 extsignature Extended signature indicating a Beck bitmap file; must be set to B (0x42) 0x03 1 controllertype Type of Beck graphics controller whose colour format this bitmap file uses; must be set to 0x01 for GC01 and GC02 0x04 4 width Width of the bitmap in pixels 0x08 4 height Height of the bitmap in pixels 0x0C 2 flags Each bit of this field indicates a flag. If a bit is set to 1, the corresponding option is considered set. All bits currently not bound to an option are reserved for future use and must be set to 0. Bit 0: The bitmap uses colour transparency. 0x0E 4 transparentcolor If the bitmap uses colour transparency all pixels having this colour will be treated as transparent pixels. If colour format uses less than 32 bit, only the lower bits will be interpreted. 0x12 4 copyrightoffset File offset of zero-terminated copyright information string; 0x00 if copyright information is not included 0x16 6 reserved Reserved for future use; must be set to all 0x00 0x1C 4 dataoffset File offset of pixel data copyrightoffset dataoffset - copyrightoffset copyrightinfo Zero-terminated string holding copyright information Can be omitted if copyrightoffset is set to 0x00 dataoffset file size - dataoffset data Pixel data Table 1 - File header 3 Pixel data The file header is followed by the intrinsic pixel data. The pixels are stored starting from the upper left corner, going from left to right and then row by row from top to bottom. The colour format of the pixels depends on the graphics controller the file is intended to be used with. Currently there s only one colour format appropriate for GC01 and GC02. This colour format uses 16 bits per pixel. The least significant 5 bits are used for the blue fraction, Copyright Beck IPC GmbH Page 3 of 5

4 the next 6 bits for the green fraction and the most significant 5 bits for the red fraction (Refer to Table 2). Note that the resulting 16 bit value is stored to the file in little endian format. Bit Colour fraction R R R R R G G G G G G B B B B B Table 2 - Colour format 4 Example As an example we will show how the following 2x2 pixel bitmap would be stored in BGB format for GC01. Image 1 - Example image Offset Value 1 Description 0x00 4A 53 Signature 0x02 42 Extended Signature 0x03 01 Controller type: GC01 etc. 0x Width: 2 pixels 0x Height: 2 pixels 0x0C No flags 0x0E No transparent colour 0x No copyright information 0x Reserved 0x1C Data file offset: 0x x20 00 F8 Pixel (0, 0): 0xF800 Red 0x22 E0 07 Pixel (0, 1): 0x07E0 Green 0x24 1F 00 Pixel (1, 0): 0x001F Blue 0x Pixel (0, 0): 0x0000 Black Table 3 - Example image in BGB format 5 History Version Date Author Comments Aug 2009 Jan Schatz First version 1 Values shown hexadecimal as stored in the file. Copyright Beck IPC GmbH Page 4 of 5

5 Copyright BECK IPC GmbH All rights reserved No part of this document may be copied or reproduced in any form or by any means without the prior written consent of BECK IPC GmbH. The information in this document is subject to change without notice. Devices sold by BECK IPC GmbH are covered by warranty and patent indemnification provisions appearing in BECK IPC GmbH Terms and Conditions of Sale only. BECK IPC GmbH MAKES NO WARRANTY, EXPRESS, STATUTORY, IMPLIED OR BY DESCRIPTION, REGARDING THE INFORMATION SET FORTH HEREIN OR REGARDING THE FREEDOM OF THE DESCRIBED DEVICES FROM INTELLECTUAL PROPERTY INFRINGEMENT. BECK IPC GmbH MAKES NO WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY PURPOSE. BECK IPC GmbH shall not be responsible for any errors that may appear in this document. BECK IPC GmbH makes no commitment to update or keep current the information contained in this document. Life critical applications - BECK products are not authorized for use as critical components in life support devices or systems unless a specific written agreement pertaining to such intended use is executed between the customer and BECK prior to use. Life support devices or systems are those which are intended for surgical implantation into the body, or which sustain life, and whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in significant injury to the user. BECK IPC GmbH customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify BECK IPC GmbH for any damages resulting from such application. Right to make changes - Beck IPC GmbH reserves the right to make changes without notice in the products, including software, described or contained herein in order to improve design and/or performance. Beck IPC GmbH assumes no responsibility or liability for the use of any of these products. Copyright Beck IPC GmbH Page 5 of 5