pngmetadata.java

Mobile 应用程序使用 Java Micro Edition (Java ME) 平台

             * use PNG_COLOR_PALETTE color type for large images.
             */ 

            if (isGray && hasAlpha && (bitDepth == 8 || bitDepth == 16)) {
                IHDR_colorType = PNGImageReader.PNG_COLOR_GRAY_ALPHA;
            } else if (isGray && !hasAlpha) {
                IHDR_colorType = PNGImageReader.PNG_COLOR_GRAY;
            } else {
                IHDR_colorType = PNGImageReader.PNG_COLOR_PALETTE;
                PLTE_present = true;
                PLTE_order = null;
                PLTE_red = (byte[])reds.clone();
                PLTE_green = (byte[])greens.clone();
                PLTE_blue = (byte[])blues.clone();

                if (hasAlpha) {
                    tRNS_present = true;
                    tRNS_colorType = PNGImageReader.PNG_COLOR_PALETTE;

                    PLTE_order = new int[alpha.length];

                    // Reorder the palette so that non-opaque entries
                    // come first.  Since the tRNS chunk does not have
                    // to store trailing 255's, this can save a
                    // considerable amount of space when encoding
                    // images with only one transparent pixel value,
                    // e.g., images from GIF sources.

                    byte[] newAlpha = new byte[alpha.length];

                    // Scan for non-opaque entries and assign them
                    // positions starting at 0.
                    int newIndex = 0;
                    for (int i = 0; i < alpha.length; i++) {
                        if (alpha[i] != (byte)255) {
                            PLTE_order[i] = newIndex;
                            newAlpha[newIndex] = alpha[i];
                            ++newIndex;
                        }
                    }
                    int numTransparent = newIndex;

                    // Scan for opaque entries and assign them
                    // positions following the non-opaque entries.
                    for (int i = 0; i < alpha.length; i++) {
                        if (alpha[i] == (byte)255) {
                            PLTE_order[i] = newIndex++;
                        }
                    }

                    // Reorder the palettes
                    byte[] oldRed = PLTE_red;
                    byte[] oldGreen = PLTE_green;
                    byte[] oldBlue = PLTE_blue;
                    int len = oldRed.length; // All have the same length
                    PLTE_red = new byte[len];
                    PLTE_green = new byte[len];
                    PLTE_blue = new byte[len];
                    for (int i = 0; i < len; i++) {
                        PLTE_red[PLTE_order[i]] = oldRed[i];
                        PLTE_green[PLTE_order[i]] = oldGreen[i];
                        PLTE_blue[PLTE_order[i]] = oldBlue[i];
                    }

                    // Copy only the transparent entries into tRNS_alpha
                    tRNS_alpha = new byte[numTransparent];
                    System.arraycopy(newAlpha, 0,
                                     tRNS_alpha, 0, numTransparent);
                }
            }
        } else {
            if (numBands == 1) {
                IHDR_colorType = PNGImageReader.PNG_COLOR_GRAY;
            } else if (numBands == 2) {
                IHDR_colorType = PNGImageReader.PNG_COLOR_GRAY_ALPHA;
            } else if (numBands == 3) {
                IHDR_colorType = PNGImageReader.PNG_COLOR_RGB;
            } else if (numBands == 4) {
                IHDR_colorType = PNGImageReader.PNG_COLOR_RGB_ALPHA;
            } else {
                throw new RuntimeException("Number of bands not 1-4!");
            }
        }

        IHDR_present = true;
    }

    public boolean isReadOnly() {
        return false;
    }

    private ArrayList cloneBytesArrayList(ArrayList in) {
        if (in == null) {
            return null;
        } else {
            ArrayList list = new ArrayList(in.size());
            Iterator iter = in.iterator();
            while (iter.hasNext()) {
                Object o = iter.next();
                if (o == null) {
                    list.add(null);
                } else {
                    list.add(((byte[])o).clone());
                }
            }

            return list;
        }
    }

    // Deep clone
    public Object clone() {
        PNGMetadata metadata;
        try {
            metadata = (PNGMetadata)super.clone();
        } catch (CloneNotSupportedException e) {
            return null;
        }
        
        // unknownChunkData needs deep clone
        metadata.unknownChunkData =
            cloneBytesArrayList(this.unknownChunkData);

        return metadata;
    }

    public Node getAsTree(String formatName) {
        if (formatName.equals(nativeMetadataFormatName)) {
            return getNativeTree();
        } else if (formatName.equals
                   (IIOMetadataFormatImpl.standardMetadataFormatName)) {
            return getStandardTree();
        } else {
            throw new IllegalArgumentException("Not a recognized format!");
        }
    }

    private Node getNativeTree() {
        IIOMetadataNode node = null; // scratch node
        IIOMetadataNode root = new IIOMetadataNode(nativeMetadataFormatName);
        
        // IHDR
        if (IHDR_present) {
            IIOMetadataNode IHDR_node = new IIOMetadataNode("IHDR");
            IHDR_node.setAttribute("width", Integer.toString(IHDR_width));
            IHDR_node.setAttribute("height", Integer.toString(IHDR_height));
            IHDR_node.setAttribute("bitDepth",
                                   Integer.toString(IHDR_bitDepth));
            IHDR_node.setAttribute("colorType",
                                   IHDR_colorTypeNames[IHDR_colorType]);
            // IHDR_compressionMethod must be 0 in PNG 1.1
            IHDR_node.setAttribute("compressionMethod",
                          IHDR_compressionMethodNames[IHDR_compressionMethod]);
            // IHDR_filterMethod must be 0 in PNG 1.1
            IHDR_node.setAttribute("filterMethod",
                                    IHDR_filterMethodNames[IHDR_filterMethod]);
            IHDR_node.setAttribute("interlaceMethod",
                              IHDR_interlaceMethodNames[IHDR_interlaceMethod]);
            root.appendChild(IHDR_node);
        }

        // PLTE
        if (PLTE_present) {
            IIOMetadataNode PLTE_node = new IIOMetadataNode("PLTE");
            int numEntries = PLTE_red.length;
            for (int i = 0; i < numEntries; i++) {
                IIOMetadataNode entry = new IIOMetadataNode("PLTEEntry");
                entry.setAttribute("index", Integer.toString(i));
                entry.setAttribute("red",
                                   Integer.toString(PLTE_red[i] & 0xff));
                entry.setAttribute("green",
                                   Integer.toString(PLTE_green[i] & 0xff));
                entry.setAttribute("blue",
                                   Integer.toString(PLTE_blue[i] & 0xff));
                PLTE_node.appendChild(entry);
            }

            root.appendChild(PLTE_node);
        }

        // bKGD
        if (bKGD_present) {
            IIOMetadataNode bKGD_node = new IIOMetadataNode("bKGD");
            
            if (bKGD_colorType == PNGImageReader.PNG_COLOR_PALETTE) {
                node = new IIOMetadataNode("bKGD_Palette");
                node.setAttribute("index", Integer.toString(bKGD_index));
            } else if (bKGD_colorType == PNGImageReader.PNG_COLOR_GRAY) {
                node = new IIOMetadataNode("bKGD_Grayscale");
                node.setAttribute("gray", Integer.toString(bKGD_gray));
            } else if (bKGD_colorType == PNGImageReader.PNG_COLOR_RGB) {
                node = new IIOMetadataNode("bKGD_RGB");
                node.setAttribute("red", Integer.toString(bKGD_red));
                node.setAttribute("green", Integer.toString(bKGD_green));
                node.setAttribute("blue", Integer.toString(bKGD_blue));
            }
            bKGD_node.appendChild(node);

            root.appendChild(bKGD_node);
        }

        // cHRM
        if (cHRM_present) {
            IIOMetadataNode cHRM_node = new IIOMetadataNode("cHRM");
            cHRM_node.setAttribute("whitePointX",
                              Integer.toString(cHRM_whitePointX));
            cHRM_node.setAttribute("whitePointY",
                              Integer.toString(cHRM_whitePointY));
            cHRM_node.setAttribute("redX", Integer.toString(cHRM_redX));
            cHRM_node.setAttribute("redY", Integer.toString(cHRM_redY));
            cHRM_node.setAttribute("greenX", Integer.toString(cHRM_greenX));
            cHRM_node.setAttribute("greenY", Integer.toString(cHRM_greenY));
            cHRM_node.setAttribute("blueX", Integer.toString(cHRM_blueX));
            cHRM_node.setAttribute("blueY", Integer.toString(cHRM_blueY));

            root.appendChild(cHRM_node);
        }

        // gAMA
        if (gAMA_present) {
            IIOMetadataNode gAMA_node = new IIOMetadataNode("gAMA");
            gAMA_node.setAttribute("value", Integer.toString(gAMA_gamma));

            root.appendChild(gAMA_node);
        }

        // hIST
        if (hIST_present) {
            IIOMetadataNode hIST_node = new IIOMetadataNode("hIST");

            for (int i = 0; i < hIST_histogram.length; i++) {
                IIOMetadataNode hist =
                    new IIOMetadataNode("hISTEntry");
                hist.setAttribute("index", Integer.toString(i));
                hist.setAttribute("value",
                                  Integer.toString(hIST_histogram[i]));
                hIST_node.appendChild(hist);
            }

            root.appendChild(hIST_node);
        }

        // iCCP
        if (iCCP_present) {
            IIOMetadataNode iCCP_node = new IIOMetadataNode("iCCP");
            iCCP_node.setAttribute("profileName", iCCP_profileName);
            iCCP_node.setAttribute("compressionMethod",
                          iCCP_compressionMethodNames[iCCP_compressionMethod]);

            Object profile = iCCP_compressedProfile;
            if (profile != null) {
                profile = ((byte[])profile).clone();
            }
            iCCP_node.setUserObject(profile);

            root.appendChild(iCCP_node);
        }

        // iTXt
        if (iTXt_keyword.size() > 0) {
            IIOMetadataNode iTXt_parent = new IIOMetadataNode("iTXt");
            for (int i = 0; i < iTXt_keyword.size(); i++) {
                Integer val;
                
                IIOMetadataNode iTXt_node = new IIOMetadataNode("iTXtEntry");
                iTXt_node.setAttribute("keyword", (String)iTXt_keyword.get(i));
                val = (Integer)iTXt_compressionFlag.get(i);
                iTXt_node.setAttribute("compressionFlag", val.toString());
                val = (Integer)iTXt_compressionMethod.get(i);
                iTXt_node.setAttribute("compressionMethod", val.toString());
                iTXt_node.setAttribute("languageTag",
                                       (String)iTXt_languageTag.get(i));
                iTXt_node.setAttribute("translatedKeyword",
                                       (String)iTXt_translatedKeyword.get(i));
                iTXt_node.setAttribute("text", (String)iTXt_text.get(i));
                
                iTXt_parent.appendChild(iTXt_node);
            }
            
            root.appendChild(iTXt_parent);
        }

        // pHYs
        if (pHYs_present) {
            IIOMetadataNode pHYs_node = new IIOMetadataNode("pHYs");
            pHYs_node.setAttribute("pixelsPerUnitXAxis",
                              Integer.toString(pHYs_pixelsPerUnitXAxis));
            pHYs_node.setAttribute("pixelsPerUnitYAxis",
                                   Integer.toString(pHYs_pixelsPerUnitYAxis));
            pHYs_node.setAttribute("unitSpecifier",
                                   unitSpecifierNames[pHYs_unitSpecifier]);

            root.appendChild(pHYs_node);
        }

        // sBIT
        if (sBIT_present) {
            IIOMetadataNode sBIT_node = new IIOMetadataNode("sBIT");

            if (sBIT_colorType == PNGImageReader.PNG_COLOR_GRAY) {
                node = new IIOMetadataNode("sBIT_Grayscale");
                node.setAttribute("gray",
                                  Integer.toString(sBIT_grayBits));
            } else if (sBIT_colorType == PNGImageReader.PNG_COLOR_GRAY_ALPHA) {
                node = new IIOMetadataNode("sBIT_GrayAlpha");
                node.setAttribute("gray",
                                  Integer.toString(sBIT_grayBits));
                node.setAttribute("alpha",
                                  Integer.toString(sBIT_alphaBits));
            } else if (sBIT_colorType == PNGImageReader.PNG_COLOR_RGB) {
                node = new IIOMetadataNode("sBIT_RGB");
                node.setAttribute("red",
                                  Integer.toString(sBIT_redBits));
                node.setAttribute("green",
                                  Integer.toString(sBIT_greenBits));
                node.setAttribute("blue",
                                  Integer.toString(sBIT_blueBits));
            } else if (sBIT_colorType == PNGImageReader.PNG_COLOR_RGB_ALPHA) {
                node = new IIOMetadataNode("sBIT_RGBAlpha");
                node.setAttribute("red",
                                  Integer.toString(sBIT_redBits));
                node.setAttribute("green",