--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dwt/internal/image/JPEGScanHeader.d	Sat Aug 09 17:00:02 2008 +0200
@@ -0,0 +1,123 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 2005 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+module dwt.internal.image;
+
+
+import dwt.DWT;
+
+final class JPEGScanHeader : JPEGVariableSizeSegment {
+    public int[][] componentParameters;
+
+public JPEGScanHeader(byte[] reference) {
+    super(reference);
+}
+
+public JPEGScanHeader(LEDataInputStream byteStream) {
+    super(byteStream);
+    initializeComponentParameters();
+}
+
+public int getApproxBitPositionHigh() {
+    return reference[(2 * getNumberOfImageComponents()) + 7] >> 4;
+}
+
+public int getApproxBitPositionLow() {
+    return reference[(2 * getNumberOfImageComponents()) + 7] & 0xF;
+}
+
+public int getEndOfSpectralSelection() {
+    return reference[(2 * getNumberOfImageComponents()) + 6];
+}
+
+public int getNumberOfImageComponents() {
+    return reference[4];
+}
+
+public int getStartOfSpectralSelection() {
+    return reference[(2 * getNumberOfImageComponents()) + 5];
+}
+
+/* Used when decoding. */
+void initializeComponentParameters() {
+    int compCount = getNumberOfImageComponents();
+    componentParameters = new int[0][];
+    for (int i = 0; i < compCount; i++) {
+        int ofs = 5 + i * 2;
+        int cid = reference[ofs] & 0xFF;
+        int dc = (reference[ofs + 1] & 0xFF) >> 4;
+        int ac = reference[ofs + 1] & 0xF;
+        if (componentParameters.length <= cid) {
+            int[][] newParams = new int[cid + 1][];
+            System.arraycopy(componentParameters, 0, newParams, 0, componentParameters.length);
+            componentParameters = newParams;
+        }
+        componentParameters[cid] = new int[] { dc, ac };
+    }
+}
+
+/* Used when encoding. */
+public void initializeContents() {
+    int compCount = getNumberOfImageComponents();
+    int[][] compSpecParams = componentParameters;
+    if (compCount is 0 || compCount !is compSpecParams.length) {
+        DWT.error(DWT.ERROR_INVALID_IMAGE);
+    }
+    for (int i = 0; i < compCount; i++) {
+        int ofs = i * 2 + 5;
+        int[] compParams = compSpecParams[i];
+        reference[ofs] = (byte)(i + 1);
+        reference[ofs + 1] = (byte)(compParams[0] * 16 + compParams[1]);
+    }
+}
+
+public void setEndOfSpectralSelection(int anInteger) {
+    reference[(2 * getNumberOfImageComponents()) + 6] = (byte)anInteger;
+}
+
+public void setNumberOfImageComponents(int anInteger) {
+    reference[4] = (byte)(anInteger & 0xFF);
+}
+
+public void setStartOfSpectralSelection(int anInteger) {
+    reference[(2 * getNumberOfImageComponents()) + 5] = (byte)anInteger;
+}
+
+public int signature() {
+    return JPEGFileFormat.SOS;
+}
+
+public bool verifyProgressiveScan() {
+    int start = getStartOfSpectralSelection();
+    int end = getEndOfSpectralSelection();
+    int low = getApproxBitPositionLow();
+    int high = getApproxBitPositionHigh();
+    int count = getNumberOfImageComponents();
+    if ((start is 0 && end is 00) || (start <= end && end <= 63)) {
+        if (low <= 13 && high <= 13 && (high is 0 || high is low + 1)) {
+            return start is 0 || (start > 0 && count is 1);
+        }
+    }
+    return false;
+}
+
+public bool isACProgressiveScan() {
+    return getStartOfSpectralSelection() !is 0 && getEndOfSpectralSelection() !is 0;
+}
+
+public bool isDCProgressiveScan() {
+    return getStartOfSpectralSelection() is 0 && getEndOfSpectralSelection() is 0;
+}
+
+public bool isFirstScan() {
+    return getApproxBitPositionHigh() is 0;
+}
+
+}