Add a color filter to grayscale images using objective a C ++ 6.0 to create a "retro image"

2 principle of Image Color Filter-pseudo-color Encoding

The name of a color filter added to an image in the digital image processing field is pseudo-color encoding. It is implemented by assigning a gray or black/white image to a special color palette. We know that for Grayscale Images, the RGB values are equal, that is, for any pixel in the image, the red component value = green component value = blue component value.

The general grayscale chart of level 1 is:

{// Regular grayscale Encoding {0, 0, 0}, {1, 1, 1}, {2, 2}, {3, 3}, // 4 {4, 4, 4}, {5, 5, 5}, {6, 6, 6}, {7, 7}, // 8 {8, 8, 8}, {9, 9}, {10, 10, 10}, {11, 11, 11}, // 12 {12, 12, 12}, {13, 13}, {14, 14}, {15, 15, 15}, // 16 {16, 16, 16}, {17, 17, 17}, {18, 18, 18}, {19, 19, 19}, // 20 {20, 20, 20}, {21, 21, 21}, {22, 22, 22}, {23, 23, 23}, // 24 ... ... ... ... {228,228,228}, {229,229,229}, {230,230,230}, {231,231,231}, // 232 {232,232,232}, {233,233,233}, {234,234,234}, {235,235,235}, // 236 {236,236,236}, {237,237,237}, {238,238,238}, {239,239,239}, // 240 {240,240,240}, {241,241,241}, {242,242,242}, {243,243,243}, // 244 {244,244,244}, {245,245,245}, {246,246,246}, {247,247,247}, // 248 {248,248,248}, {249,249,249}, {250,250,250}, {251,251,251}, // 252 {252,252,252}, {253,253,253}, {254,254,254}, {255,255,255}, // 256 } // Rule: r = G = B = I, for I = 0 to 255

3 Programming

The following uses the 256-level grayscale image "angel.bmp" as an example to describe the main steps and key functions written with VC ++ 6.0. The program passes debugging in the Windows 2000 environment of the PC, and achieved good color effect.

(1) create a Main Interface

Create a single document project in the MFC Appwizard Wizard of VC. The base class of cfunnyview is cformview, And the menu attribute is modified.

Figure 1

The function that is executed when you click the "color encoding" menu on the main interface:

Void cfunnyglassview: onenhacolor () { // Todo: add your command handler code here // Pseudo-color Encoding // Obtain the document Cfunnyglassdoc * pdoc = getdocument (); Int ncolor; // Save the user-selected pseudo-color-coded table Index Lpstr lpdib; // pointer to Dib Lpdib = (lpstr): globallock (hglobal) pdoc-> gethdib (); // lock Dib // Determine whether it is a 8-bpp Bitmap (only processing the pseudo-color conversion of the 256-color bitmap, and so on) Cdlgcolor dlgpara; // parameter dialog box // Initialize the variable value If (pdoc-> m_ncolorindex> = 0) { // Initially select the current pseudo color Dlgpara. m_ncolor = pdoc-> m_ncolorindex; } Else { // The phased-out pseudo-color encoding table is selected. Dlgpara. m_ncolor = 0; } // Pointer to the name Array Dlgpara. m_lpcolorname = (lpstr) colorscalename; // Number of pseudo-color codes Dlgpara. m_ncolorcount = color_scale_count; // Name String Length Dlgpara. m_nnamelen = sizeof (colorscalename)/color_scale_count; // Displayed dialog box, prompting you to set the translation volume If (dlgpara. domodal ()! = Idok) { Return; // return } Ncolor = dlgpara. m_ncolor; // get user settings Delete dlgpara; // Delete dialog box Beginwaitcursor (); // modify the cursor shape // Determine whether the pseudo-color encoding is changed If (pdoc-> m_ncolorindex! = Ncolor) { // Call the replacecolorpal () function to change the color palette : Replacecolorpal (lpdib, (byte *) colorstable [ncolor]); Pdoc-> getdocpalette ()-> setpaletteentries (0,256, (lppaletteentry) colorstable [ncolor]); // Replace the current document palette Pdoc-> m_ncolorindex = ncolor; // update the class member variable // Set the dirty flag pdoc-> setmodifiedflag (true ); Ondorealize (wparam) m_hwnd, 0); // implement a new palette Pdoc-> updateallviews (null); // update the view } : Globalunlock (hglobal) pdoc-> gethdib (); // unlock Endwaitcursor (); // restore the cursor }

(2) create a dialog box

The "idc_color_list" dialog box is titled "select filter color:" and add a ListBox control and two command buttons "OK" and "cancel ".

2

Main functions processed in the idc_color_list dialog box:

I. Initialization dialog box

Bool cdlgcolor: oninitdialog () { Cdialog: oninitdialog (); Int I; // Add pseudo-color Encoding For (I = 0; I <m_ncolorcount; I ++) { M_lstcolor.addstring (m_lpcolorname + I * m_nnamelen ); } // Select the initial encoding table M_lstcolor.setcursel (m_ncolor ); Return true; // return true unless you set the focus to a control // Exception: OCX property pages shold return false }

Ii. When the user determines the selected code table, execute the following functions:

Void cdlgcolor: onok () { // Todo: add extra validation here // Click OK. M_ncolor = m_lstcolor.getcursel (); Cdialog: onok (); }

(3) pseudo-color code table File

// Number of encoded tables # Define color_scale_count 6 // Encode the table name Const char colorscalename [color_scale_count] [64] = { "1 conventional grayscale encoding ", "2 inverse grayscale encoding ", "3 red saturation encoding ", "4 Green saturation encoding ", "5 blue saturation encoding ", "6 Yellow saturation encoding ", "7 cyan saturation encoding ", "8 purple saturation encoding ", }; // Encode the RGB array of the table Const byte colorstable [color_scale_count] [1, 256] [4] = { {// Red saturation code {0, 0, 0}, {1, 0, 0}, {2, 0, 0}, {3, 0, 0}, // 4 {4, 0, 0}, {5, 0, 0}, {6, 0, 0}, {7, 0, 0}, // 8 {8, 0, 0}, {9, 0, 0}, {10, 0, 0}, {11, 0, 0}, // 12 {12, 0, 0}, {13, 0, 0}, {14, 0, 0}, {15, 0, 0}, // 16 {16, 0, 0}, {17, 0, 0}, {18, 0, 0}, {19, 0, 0}, // 20 ... ... ... ... {224, 0, 0}, {225, 0, 0}, {226, 0, 0}, {227, 0, 0}, // 228 {228, 0, 0}, {229, 0, 0}, {230, 0, 0}, {231, 0, 0}, // 232 {232, 0, 0}, {233, 0, 0}, {234, 0, 0}, {235, 0, 0}, // 236 {236, 0, 0}, {237, 0, 0}, {238, 0, 0}, {239, 0, 0}, // 240 {240, 0, 0}, {241, 0, 0}, {242, 0, 0}, {243, 0, 0}, // 244 {244, 0, 0}, {245, 0, 0}, {246, 0, 0}, {247, 0, 0}, // 248 {248, 0, 0}, {249, 0, 0}, {250, 0, 0}, {251, 0, 0}, // 252 {252, 0, 0}, {253, 0, 0}, {254, 0, 0}, {255, 0, 0}, // 256 }, // Rule: r = I, G = B = 0; I = 0 to 255 {// Green saturation Encoding {0, 0, 0}, {0, 1, 0}, {0, 2, 0}, {0, 3, 0}, // 4 {0, 4, 0}, {0, 5, 0}, {0, 6, 0}, {0, 7, 0}, // 8 {0, 8, 0}, {0, 9, 0}, {0, 10, 0}, {0, 11, 0}, // 12 {0, 12, 0}, {0, 13, 0}, {0, 14, 0}, {0, 15, 0}, // 16 {0, 16, 0}, {0, 17, 0}, {0, 18, 0}, {0, 19, 0}, // 20 {0, 20, 0}, {0, 21, 0}, {0, 22, 0}, {0, 23, 0}, // 24 ... ... ... ... {0,224, 0}, {0,225, 0}, {0,226, 0}, {0,227, 0}, // 228 {0,228, 0}, {0,229, 0}, {0,230, 0}, {0,231, 0}, // 232 {0,232, 0}, {0,233, 0}, {0,234, 0}, {0,235, 0}, // 236 {0,236, 0}, {0,237, 0}, {0,238, 0}, {0,239, 0}, // 240 {0,240, 0}, {0,241, 0}, {0,242, 0}, {0,243, 0}, // 244 {0,244, 0}, {0,245, 0}, {0,246, 0}, {0,247, 0}, // 248 {0,248, 0}, {0,249, 0}, {0,250, 0}, {0,251, 0}, // 252 {0,252, 0}, {0,253, 0}, {0,254, 0}, {0,255, 0}, // 256 }, // Law: g = I, r = B = 0; for I = 0 to 255 {// Blue saturation Encoding {0, 0, 0}, {0, 0, 1}, {0, 0, 2}, {0, 0, 3}, // 4 {0, 0, 4}, {0, 0, 5}, {0, 0, 6}, {0, 0, 7}, // 8 {0, 0, 8}, {0, 0, 9}, {0, 0, 10}, {0, 0, 11}, // 12 {0, 0, 12}, {0, 0, 13}, {0, 0, 14}, {0, 0, 15}, // 16 {0, 0, 16}, {0, 0, 17}, {0, 0, 18}, {0, 0, 19}, // 20 {0, 0, 20}, {0, 0, 21}, {0, 0, 22}, {0, 0, 23}, // 24 ... ... ... ... {0, 0,244}, {0, 0,245}, {0, 0,246}, {0, 0,247}, // 248 {0, 0,248}, {0, 0,249}, {0, 0,250}, {0, 0,251}, // 252 {0, 0,252}, {0, 0,253}, {0, 0,254}, {0, 0,255}, // 256 }, // Rule: B = I, r = G = 0; for I = 0 to 255 {// Yellow saturation code {0, 0, 0}, {1, 1, 0}, {2, 2, 0}, {3, 3, 0}, // 4 {4, 4, 0}, {5, 5, 0}, {6, 6, 0}, {7, 7, 0}, // 8 {8, 8, 0}, {9, 9, 0}, {10, 10, 0}, {11, 11, 0}, // 12 {12, 12, 0}, {13, 13, 0}, {14, 14, 0}, {15, 15, 0}, // 16 {16, 16, 0}, {17, 17, 0}, {18, 18, 0}, {19, 19, 0}, // 20 {20, 20, 0}, {21, 21, 0}, {22, 22, 0}, {23, 23, 0}, // 24 ... ... ... ... {228,228, 0}, {229,229, 0}, {230,230, 0}, {231,231, 0}, // 232 {232,232, 0}, {233,233, 0}, {234,234, 0}, {235,235, 0}, // 236 {236,236, 0}, {237,237, 0}, {238,238, 0}, {239,239, 0}, // 240 {240,240, 0}, {241,241, 0}, {242,242, 0}, {243,243, 0}, // 244 {244,244, 0}, {245,245, 0}, {246,246, 0}, {247,247, 0}, // 248 {248,248, 0}, {249,249, 0}, {250,250, 0}, {251,251, 0}, // 252 {252,252, 0}, {253,253, 0}, {254,254, 0}, {255,255, 0}, // 256 }, // Rule: r = G = I, B = 0; for I = 0 to 255 {// Cyan saturation Encoding {0, 0, 0}, {0, 1, 1}, {0, 2, 2}, {0, 3, 3}, // 4 {0, 4, 4}, {0, 5, 5}, {0, 6, 6}, {0, 7}, // 8 {0, 8, 8}, {0, 9}, {0, 10}, {0, 11}, // 12 {0, 12, 12}, {0, 13, 13}, {0, 14, 14}, {0, 15, 15}, // 16 {0, 16, 16}, {0, 17, 17}, {0, 18, 18}, {0, 19, 19}, // 20 {0, 20, 20}, {0, 21, 21}, {0, 22, 22}, {0, 23, 23}, // 24 {0, 24, 24}, {0, 25, 25}, {0, 26, 26}, {0, 27, 27}, // 28 ... ... ... ... {0,232,232}, {0,233,233}, {0,234,234}, {0,235,235}, // 236 {0,236,236}, {0,237,237}, {0,238,238}, {0,239,239}, // 240 {0,240,240}, {0,241,241}, {0,242,242}, {0,243,243}, // 244 {0,244,244}, {0,245,245}, {0,246,246}, {0,247,247}, // 248 {0,248,248}, {0,249,249}, {0,250,250}, {0,251,251}, // 252 {0,252,252}, {0,253,253}, {0,254,254}, {0,255,255}, // 256 }, // Rule: B = G = I, r = 0; for I = 0 to 255 {// Purple saturation Encoding {0, 0, 0}, {1, 0, 1}, {2, 0, 2}, {3, 0, 3}, // 4 {4, 0, 4}, {5, 0, 5}, {6, 0, 6}, {7, 0, 7}, // 8 {8, 0, 8}, {9, 0, 9}, {10, 0, 10}, {11, 0, 11}, // 12 {12, 0, 12}, {13, 0, 13}, {14, 0, 14}, {15, 0, 15}, // 16 {16, 0, 16}, {17, 0, 17}, {18, 0, 18}, {19, 0, 19}, // 20 {20, 0, 20}, {21, 0, 21}, {22, 0, 22}, {23, 0, 23}, // 24 ... ... ... ... {228, 0,228}, {229, 0,229}, {230, 0,230}, {231, 0,231}, // 232 {232, 0,232}, {233, 0,233}, {234, 0,234}, {235, 0,235}, // 236 {236, 0,236}, {237, 0,237}, {238, 0,238}, {239, 0,239}, // 240 {240, 0,240}, {241, 0,241}, {242, 0,242}, {243, 0,243}, // 244 {244, 0,244}, {245, 0,245}, {246, 0,246}, {247, 0,247}, // 248 {248, 0,248}, {249, 0,249}, {250, 0,250}, {251, 0,251}, // 252 {252, 0,252}, {253, 0,253}, {254, 0,254}, {255, 0,255}, // 256 } // Rule: r = B = I, G = 0; for I = 0 to 255 // End the encoding table };