Beispiel #1
0
        internal int Read(IDataStream data)
        {
            int count = 0;

            int length = data.Get16();

            count += 2;

            Precision = data.Get8();
            count++;

            DimY   = data.Get16();
            count += 2;

            DimX   = data.Get16();
            count += 2;

            NumComponents = data.Get8();
            count++;

            //components = new ComponentSpec[numComp]; // some image exceed this range...
            Components = new ComponentSpec[256]; // setting to 256 -- not sure what it should be.

            for (int i = 1; i <= NumComponents; i++)
            {
                if (count > length)
                {
                    throw new IOException("ERROR: frame format error");
                }

                int c = data.Get8();
                count++;

                if (count >= length)
                {
                    throw new IOException("ERROR: frame format error [c>=Lf]");
                }

                int temp = data.Get8();
                count++;

                if (Components[c] == null)
                {
                    Components[c] = new ComponentSpec();
                }

                Components[c].hSamp         = temp >> 4;
                Components[c].vSamp         = temp & 0x0F;
                Components[c].quantTableSel = data.Get8();
                count++;
            }

            if (count != length)
            {
                throw new IOException("ERROR: frame format error [Lf!=count]");
            }

            return(1);
        }
Beispiel #2
0
        internal int Read(IDataStream data)
        {
            int count  = 0;
            int length = data.Get16();

            count += 2;

            NumComponents = data.Get8();
            count++;

            components = new ScanComponent[NumComponents];

            for (int i = 0; i < NumComponents; i++)
            {
                components[i] = new ScanComponent();

                if (count > length)
                {
                    throw new IOException("ERROR: scan header format error");
                }

                components[i].ScanCompSel = data.Get8();
                count++;

                int tempval = data.Get8();
                count++;

                components[i].DcTabSel = tempval >> 4;
                components[i].AcTabSel = tempval & 0x0F;
            }

            Selection = data.Get8();
            count++;

            SpectralEnd = data.Get8();
            count++;

            int temp = data.Get8();

            Ah = temp >> 4;
            Al = temp & 0x0F;
            count++;

            if (count != length)
            {
                throw new IOException("ERROR: scan header format error [count!=Ns]");
            }

            return(1);
        }
Beispiel #3
0
        internal int Read(IDataStream data, int[] table)
        {
            int count  = 0;
            int length = data.Get16();

            count += 2;

            while (count < length)
            {
                int temp = data.Get8();
                count++;
                int t = temp & 0x0F;

                if (t > 3)
                {
                    throw new IOException("ERROR: Quantization table ID > 3");
                }

                _precision[t] = temp >> 4;

                if (_precision[t] == 0)
                {
                    _precision[t] = 8;
                }
                else if (_precision[t] == 1)
                {
                    _precision[t] = 16;
                }
                else
                {
                    throw new IOException("ERROR: Quantization table precision error");
                }

                _tq[t] = 1;

                if (_precision[t] == 8)
                {
                    for (int i = 0; i < 64; i++)
                    {
                        if (count > length)
                        {
                            throw new IOException("ERROR: Quantization table format error");
                        }

                        quantTables[t][i] = data.Get8();
                        count++;
                    }

                    EnhanceQuantizationTable(quantTables[t], table);
                }
                else
                {
                    for (int i = 0; i < 64; i++)
                    {
                        if (count > length)
                        {
                            throw new IOException("ERROR: Quantization table format error");
                        }

                        quantTables[t][i] = data.Get16();
                        count            += 2;
                    }

                    EnhanceQuantizationTable(quantTables[t], table);
                }
            }

            if (count != length)
            {
                throw new IOException("ERROR: Quantization table error [count!=Lq]");
            }

            return(1);
        }
Beispiel #4
0
        internal int Read(IDataStream data, int[, ][] HuffTab)
        {
            int count  = 0;
            int length = data.Get16();

            count += 2;

            while (count < length)
            {
                int temp = data.Get8();
                count++;
                int t = temp & 0x0F;
                if (t > 3)
                {
                    throw new IOException("ERROR: Huffman table ID > 3");
                }

                int c = temp >> 4;
                if (c > 2)
                {
                    throw new IOException("ERROR: Huffman table [Table class > 2 ]");
                }

                _th[t]    = 1;
                _tc[t, c] = 1;

                for (int i = 0; i < 16; i++)
                {
                    _l[t, c][i] = data.Get8();
                    count++;
                }

                for (int i = 0; i < 16; i++)
                {
                    for (int j = 0; j < _l[t, c][i]; j++)
                    {
                        if (count > length)
                        {
                            throw new IOException("ERROR: Huffman table format error [count>Lh]");
                        }
                        _v[t, c][i, j] = data.Get8();
                        count++;
                    }
                }
            }

            if (count != length)
            {
                throw new IOException("ERROR: Huffman table format error [count!=Lf]");
            }

            for (int i = 0; i < 4; i++)
            {
                for (int j = 0; j < 2; j++)
                {
                    if (_tc[i, j] != 0)
                    {
                        BuildHuffTable(HuffTab[i, j], _l[i, j], _v[i, j]);
                    }
                }
            }

            return(1);
        }