rpfframe.java

openmap java写的开源数字地图程序. 用applet实现,可以像google map 那样放大缩小地图.

            binFile.seek(0);

            // Read the NITF part of the file...
            nitfHeader = new NitfHeader();
            // If false, it might not be a NITF file, start over...
            if (!nitfHeader.read(binFile))
                binFile.seek(0);

            header = new RpfHeader();
            // Now, read the RPF header...
            if (!header.readHeader(binFile))
                return false;

            /* Check date for validity: date should be "1993xxxx" */
            if (!header.standardDate.startsWith("199")
                    && !header.standardDate.startsWith("20")) {
                Debug.output("RpfFrame.read: Invalid date in header: "
                        + header.standardDate);
                return false;
            }

            // Need to do this right after the header...
            binFile.seek(header.locationSectionLocation);
            fileSections = new RpfFileSections(binFile);

            RpfFileSections.RpfLocationRecord[] loc = fileSections.getLocations(RpfFileSections.FRAME_LOCATION_KEY);

            attributes = fileSections.parseAttributes(binFile);
            coverage = fileSections.parseCoverageSection(binFile);

            colortable = new RpfColortable();
            getColors(binFile, colortable);

            /* DKS: from index to componentLocation */
            if (loc[0] == null) {
                Debug.output("RpfFrame: No compression section!");
                return false;
            }

            /* Read the compression tables */
            binFile.seek(loc[0].componentLocation);
            compression = new Compression(binFile);
            if (DEBUG_RPFDETAIL)
                Debug.output(compression.toString());

            if (loc[2] == null) {
                Debug.output("Warning: Can't find compr. lookup subsection in FrameFile:");
                Debug.output("   Using alternate computation");
                /* length of compr. sect. subhdr = 10 */
                binFile.seek(loc[0].componentLocation + 10);
            } else {
                /*
                 * DKS: Position at start of compression lookup table
                 * offset record
                 */
                if (DEBUG_RPFDETAIL) {
                    Debug.output("Comp lkup subsect: loc[2].componentLocation(264?): "
                            + loc[2].componentLocation);
                }
                binFile.seek(loc[2].componentLocation);
            }

            /* 2 new hdr fields */

            lookupOffsetTableOffset = (long) binFile.readInteger();
            lookupTableOffsetRecLen = (int) binFile.readShort();

            if (DEBUG_RPFDETAIL) {
                Debug.output("lookupOffsetTableOffset(6): "
                        + lookupOffsetTableOffset);
                Debug.output("lookupTableOffsetRecLen(14): "
                        + lookupTableOffsetRecLen);
            }

            /* For each compression table */
            for (i = 0; i < 4; i++) {
                lookupTable[i] = new LookupTable(binFile);
                if (DEBUG_RPFDETAIL) {
                    Debug.output("Compression lookup table offset record " + i);
                    Debug.output(lookupTable[i].toString());
                }

                if (lookupTable[i].records != 4096
                        || lookupTable[i].values != 4
                        || lookupTable[i].bitLength != 8) {
                    Debug.output("RpfFrame: Bad VQ info in compression record");
                    return false;
                }
            } /* for i */

            for (i = 0; i < 4; i++) { /* Read compression lookup table */
                /*
                 * new position from compression lookup subsection:
                 * loc[2]
                 */
                binFile.seek(loc[2].componentLocation + lookupTable[i].offset);
                if (DEBUG_RPFDETAIL) {
                    currentPos = binFile.getFilePointer();
                    Debug.output("Read compr. lookup table (4x4096) at position: "
                            + currentPos);
                }
                for (j = 0; j < 4096; j++)
                    table[i][j] = binFile.readBytes(4, false);

            } /*
               * for i=1 to 4 (# compression tables, 1 for each pixel
               * row)
               */

            /* seek to LOC_ATTRIB_SUBHEADER, ID=141 */
            if ((Dchum) && (chumVersion > 1)) { /*
                                                 * Chum selected and
                                                 * file version > 1
                                                 */
                if (loc[6] == null) {
                    Debug.output("RpfFrame: Can't find ATTRIBUTE_SUBHEADER section!");
                    return false;
                }
                if (DEBUG_RPFDETAIL)
                    Debug.output("ATTRIBUTE SUBHEADER location: "
                            + loc[6].componentLocation);

                binFile.seek(loc[6].componentLocation);

                numAttributeOffsetRecs = (int) binFile.readShort();
                if (DEBUG_RPFDETAIL)
                    Debug.output("numAttributeOffsetRecs: "
                            + numAttributeOffsetRecs);

                /* Go to Attrib subsection */
                if (loc[7] == null) {
                    Debug.output("RpfFrame: Can't find ATTRIBUTE_SECTION in Frame file");
                    return false;
                }

                if (DEBUG_RPFDETAIL)
                    Debug.output("ATTRIBUTE SECTION location: "
                            + loc[7].componentLocation);

                binFile.seek(loc[7].componentLocation);

                descCount = 0; /* # descriptor strings so far */

                for (i = 0; i < numAttributeOffsetRecs; i++) {
                    attributeId = (int) binFile.readShort();
                    attributeParamId = binFile.read();
                    /**int tempc = */binFile.read(); // uchar
                    attributeRecOffset = (long) binFile.readInteger();

                    /* # subframes impacted */
                    if ((attributeId == 24) && (attributeParamId == 4)) {
                        /* save file loc */
                        fsave = binFile.getFilePointer();
                        /* Go to proper spot in attrib section */
                        binFile.seek(loc[7].componentLocation
                                + attributeRecOffset);
                        /* read # subframes impacted */
                        numSubframesChummed = (int) binFile.readShort();

                        if (DEBUG_RPFDETAIL) {
                            Debug.output("n_attrib_chummedSubframe: "
                                    + numSubframesChummed);
                        }
                        /* Read list of subframes chummed */
                        /* Assume these are next in file */
                        for (j = 0; j < numSubframesChummed; j++) {
                            chummedSubframe = (int) binFile.readShort();

                            if (DEBUG_RPFDETAIL) {
                                Debug.output("chummedSubframe: "
                                        + chummedSubframe);
                            }

                            /* y,x */
                            chummed[chummedSubframe / 6][chummedSubframe % 6] = true;
                        } /* for j */
                        binFile.seek(fsave); /* restore file pos */
                    } /* if 24,4 */

                    /* Update date */
                    if ((attributeId == 24) && (attributeParamId == 3)) {
                        /* save file loc */
                        fsave = binFile.getFilePointer();
                        /* Go to proper spot in attrib section */
                        binFile.seek(loc[7].componentLocation
                                + attributeRecOffset);
                        /* read date */
                        descriptorDates[descCount] = binFile.readFixedLengthString(8);

                        if (DEBUG_RPFDETAIL)
                            Debug.output("descriptorDate: "
                                    + descriptorDates[descCount]);

                        binFile.seek(fsave); /* restore file pos */
                    } /* if 24,3 */

                    /* # chars in descriptor */
                    if ((attributeId == 24) && (attributeParamId == 6)) {
                        /* save file loc */
                        fsave = binFile.getFilePointer();
                        /* Go to proper spot in attrib section */
                        binFile.seek(loc[7].componentLocation
                                + attributeRecOffset);
                        /* read # chars in descriptor */

                        numCharsInDesc = (int) binFile.readShort();

                        if (DEBUG_RPFDETAIL) {
                            Debug.output("Prepare to fread descriptors[descCount]");
                            Debug.output("RpfFrame.read: descCount: "
                                    + descCount);
                        }

                        descriptors[descCount] = binFile.readFixedLengthString(numCharsInDesc);

                        /* Array of strings, not 2-d array !!!!???? */
                        if (DEBUG_RPFDETAIL) {
                            Debug.output("descriptors[descCount]: "
                                    + descriptors[descCount]);
                        }
                        descCount++; /* string number */

                        binFile.seek(fsave); /* restore file pos */
                    } /* if 24,6 */
                } /* for i */
            } /* if Dchum */

            /* READ THE IMAGE DATA */
            if (DEBUG_RPFDETAIL) {
                Debug.output("Image descr. subheader location: loc[1].componentLocation(68576?): "
                        + loc[1].componentLocation);
            }
            binFile.seek(loc[1].componentLocation);
            image = new Image(binFile);

            /* New, DKS. NULL (FF) if no subfr mask table */
            subframeMaskTableOffset = binFile.readInteger();

            if (DEBUG_RPFDETAIL) {
                Debug.output(image.toString());
                Debug.output("subframeMaskTableOffset: "
                        + subframeMaskTableOffset);
            }

            if (subframeMaskTableOffset == 0) { /* ERROR Check */
                Debug.error("RpfFrame.read(): subframeMaskTableOffset==0.");
                return false;
            }

            if (subframeMaskTableOffset == 0xFFFFFFFF)
                allSubframes = true;
            else
                allSubframes = false;

            if (Debug.debugging("rpfframe")) {
                Debug.output("allSubframes: " + allSubframes);
            }

            if (!allSubframes) { /* Read mask data */
                /* fseek to LOC_MASK_SUBSECTION, ID=138 */
                if (loc[5] == null) {
                    Debug.error("RpfFrame.read(): Can't find MASK_SUBSECTION section in Frame file");
                    return false;
                }
                if (DEBUG_RPFDETAIL) {
                    Debug.output("MASK SUBSECTION location: "
                            + loc[5].componentLocation);
                }

                binFile.seek(loc[5].componentLocation + subframeMaskTableOffset);

                for (i = 0; i < 6; i++) { /* y */
                    for (j = 0; j < 6; j++) {
                        subframeOffset[i][j] = (long) binFile.readInteger();
                        if (subframeOffset[i][j] == 0xFFFFFFFF)
                            masked[i][j] = true; /* subfr masked */

                        if (DEBUG_RPFDETAIL) {
                            Debug.output("i:" + i + ", j:" + j
                                    + ", masked[i][j]: " + masked[i][j]);
                        }

                    } /* for j */
                } /* for i */
            } /* if !allSubframes */

            if (image.vertSubframes != 6 || image.horizSubframes != 6) {
                Debug.output("Not 6x6 subframes per frame: must be masked.");
            }

            // int rowBytes = 256 / 4 * 3 / 2;
            
            // Is this section needed??
            /* fseek to LOC_IMAGE_DISPLAY_PARAM_SUBHEADER, ID=137 */
            if (loc[4] == null) {
                Debug.error("RpfFrame.read(): Can't find IMAGE_DISPLAY_PARAM_SUBHEADER section!");
                return false;
            }

            /* Image Display Parameters Subheader */
            if (DEBUG_RPFDETAIL) {
                Debug.output("IMAGE Display params subheader location: "
                        + loc[4].componentLocation);
            }
            binFile.seek(loc[4].componentLocation);

            /* Go to start of image spatial data subsection */
            if (loc[3] == null) {
                Debug.output("WARNING: Can't find Image spatial data subsection in FrameFile:");
                Debug.output("   Using alternate computation");
                /*
                 * DKS. skip 14 bytes of image display parameters
                 * subheader instead
                 */
                binFile.seek(loc[4].componentLocation + 14);
            } else {
                /*
                 * DKS: Position at start of image spatial data
                 * subsection
                 */
                currentPos = binFile.getFilePointer();
                if (DEBUG_RPFDETAIL) {
                    Debug.output("Current frame file position(68595?): "
                            + currentPos);
                    Debug.output("Image spatial data subsect: loc[3](68609?): "
                            + loc[3].componentLocation);
                }

                binFile.seek(loc[3].componentLocation);
            } /* else */

            /* Read subframes from top left, row-wise */
            for (i = 0; i < 6; i++) { /* row */
                for (j = 0; j < 6; j++) { /* col */
                    /* DKS. New: init indices to valid subframes */
                    indices[i][j] = i * 6 + j;
                    /* (256/4)=64. 64*64 * 12bits / 8bits = 6144 bytes */
                    if (!masked[i][j]) {
                        compressedSubframe[i][j] = binFile.readBytes(6144,
                                false);
                        if (DEBUG_RPFDETAIL)
                            Debug.output(" i:" + i + ", j:" + j
                                    + ", read image data. rc(6144):"
                                    + compressedSubframe[i][j].length);
                    } else
                        compressedSubframe[i][j] = new byte[6144];
                }
            }
            
        } catch (IOException e) {
            Debug.error("RpfFrame: read(): File IO Error!\n" + e);
            return false;
        } catch (FormatException f) {
            Debug.error("RpfFrame: read(): File IO Format error!" + f);
            return false;
        }

        if (DEBUG_RPFDETAIL) {
            Debug.output("LEAVE RPFFRAME.READ");
        }

        valid = true;
        return valid;
    } /* read */

    static public class Compression {
        public int algorithm;//ushort