Convert custom bitmap to CBitmap/CImage bits format

I got an custom bitmap format, serialized (read) into file, just like that:

Code:

---

std::ifstream file(filename, std::ios::binary);

int Height, Width;
file >> Width >> Height;

float scale;
file >> scale;
scale = fabs(scale);

for (int h = 0; h < Height; ++h)
{
        for (int w = 0; w < Width; ++w)
        {
                for (int c = 0; c < C; ++c)
                {
                        float x;
                        file.read((char*)&x, sizeof(float));
                        image[((Height - 1 - h) * Width + w) * C + c] = x * scale;
                }
        }
}

---

where image is an object that has as constructor CImage(int width, int height, int channels).
Now, I should load this data into a CImage (or CBitmap) MFC object in order to display it. And I know that CImage has CImage::SetPixel method: https://docs.microsoft.com/en-us/cpp...-2019#setpixel, but I don't know how to use it in this case ...

Can you help me to setup CImage pixels to have that custom data valid into CImage object ? I had take a look over CImage::GetBits and CImage::GetPitch methods to see how to arrange data into CImage, but I didn't get it ... (just order way, and data range).

I guess I found a way ... but I cannot test yet ...
The solution that I wrote it:

Code:

---

CImage image;
image.Create((int)W, (int)H, (int)scale);
for (int h = 0; h < H; ++h)
{
        for (int w = 0; w < W; ++w)
        {
                for (int c = 0; c < C; ++c)
                {
                        float x;
                        file.read((char*)&x, sizeof(float));
                        image.SetPixel(w, h, (COLORREF)(x * scale));
                }
        }
}

---

I don't know if is correct though ...

P.S. The title should be viceversa: from custom format to CImage.

Quote:

---

Originally Posted by mesajflaviu

P.S. The title should be viceversa: from custom format to CImage.

---

Done.

I still have a little question, very valuable question: how to convert COLORREF into channel ? The custom bitmap object need width, height and channel:

Code:

---

CustomObject(int width, int height, int channels)

---

the CImage has GetPixel method, that has width and height parameters, but return COLORREF ... and I need to convert it into channel (in fact float, or int) ... how can I do that ?

What is CustomObject? Where and how is it defined?

CustomObject is a custom bitmap class, and is defined as below:

Code:

---

                CustomObject()
                        : width(0),
                        height(0),
                        channels(0) {}

                CustomObject(int width, int height, int channels)
                        : data(width * height * channels),
                        width(width),
                        height(height),
                        channels(channels) {}

---

where data is std::vector<float> data;

Is it your own class?
What is the physical meaning of "channels"?

No, it is not developed by me ... is a part of a project.

The only members of this CustomObject class is

Code:

---

        private:
                std::vector<float> data;
                int width;
                int height;
                int channels;

---

and I need to populate CustomObject with a CImage data ...

Quote:

---

Originally Posted by mesajflaviu

No, it is not developed by me ... is a part of a project.

The only members of this CustomObject class is

Code:

---

        private:
                std::vector<float> data;
                int width;
                int height;
                int channels;

---

and I need to populate CustomObject with a CImage data ...

---

Then ask the project designers about the meaning of "channels". :rolleyes:

The only way to know what is this member is to look into code source. And channel member is used like this:

Code:

---

std::vector<float> data;
data = width * height * channel;

---

and when this object is serialized on file, the source code tell the user:

Code:

---

// header
int getChannels() const { return channels; }

---

and

Code:

---

// cpp, serialize on file
if (customobject.getChannels() != 3)
        throw std::invalid_argument("image must have 3 channels");

---

that is all I know about this member: channel. I know, it is not enough ... that is why I struggle to put this data into CImage ...

Quote:

---

Originally Posted by mesajflaviu

...

Code:

---

// cpp, serialize on file
if (customobject.getChannels() != 3)
        throw std::invalid_argument("image must have 3 channels");

---

that is all I know about this member: channel. I know, it is not enough ... that is why I struggle to put this data into CImage ...

---

Then pass in 3 as the channels.

The difference between CImage and CCustomBitmap is that CImage store bytes on bi-dimensional array (width and height), and CCustomBitmap store bits on three-dimensional array (width, height and channel). From this reason, I don't know if I could make a conversion between CImage and CCustomBitmap and viceversa .... or I am wrong ?
See how is de-serialize (read) CCustomBitmap object:

Code:

---

int Channel = 3;
int Height, Width;
file >> Width >> Height;

float fScale;
file >> fScale;                        // fScale is always -1
fScale = fabs(fScale);        // now fScale is 1.0

// Read the pixels
ImageBuffer image(Width, Height, Channel);

for (int h = 0; h < Height; ++h)
{
        for (int w = 0; w < Width; ++w)
        {
                for (int c = 0; c < Channel; ++c)
                {
                        float x;
                        file.read((char*)&x, sizeof(float));
                        image[((Height - 1 - h) * Width + w) * Channel + c] = x * fScale;  // fScale is 1
                }
        }
}

---

and I tried to de-serialize (read) the CCustomBitmap from CImage

Code:

---

CImage image;
int Channel = 3;
// Read the pixels
int Width = image.GetWidth(), Height = image.GetHeight();
ImageBuffer imageBuff(Width, Height, Channel);

for (int h = 0; h < Height; ++h)
{
        for (int w = 0; w < Width; ++w)
        {
                for (int c = 0; c < Channel; ++c)
                {
                        int x = static_cast<int>(image.GetPixel(w, h));
                        imageBuff[((Height - 1 - h) * Width + w) * Channel + c] = static_cast<float>(x);
                }
        }
}

---

but is not correct (I load this result into an app that can read CCustomBitmap file and the image is white) ... Do I have a chance to make it ?

On the third level, I tried to put the same CImage data:

Code:

---

for (int c = 0; c < Channel; ++c)
{
        int x = static_cast<int>(image.GetPixel(w, h));
        imageBuff[((Height - 1 - h) * Width + w) * Channel + c] = static_cast<float>(x);
}

---

but seem to not work ...

Sorry to not help you. But it is only because I have no idea what the physical meaning of the "channel" is.

I am open to give any information that I got about this member variable, but this is only from source code, is the only information source. I come back little bit later.

@VictorN: you helped me a lot in the past and I thank you. Even if you have enough time to answer me or not, from respect to you I'll try to explain as much as I could of what is about this variable:

The definition of this class is

Code:

---

        class CCustomBitmap
        {
        private:
                std::vector<float> data;
                int m_nWidth;
                int m_nHeight;
                int channels;

        public:
                CCustomBitmap()
                        : m_nWidth(0),
                        m_nHeight(0),
                        channels(0) {}

                CCustomBitmap(int m_nWidth, int m_nHeight, int channels)
                        : data(m_nWidth * m_nHeight * channels),
                        m_nWidth(m_nWidth),
                        m_nHeight(m_nHeight),
                        channels(channels) {}

                const float& operator [](size_t i) const { return data[i]; }
                float& operator [](size_t i) { return data[i]; }

                int getChannels() const { return channels; }
        ....
        }

---

channels is declared here but seem not be involved into serializing method:

Code:

---

        CCustomBitmap loadImage(const std::string& filename)
        {
                std::ifstream file(filename, std::ios::binary);
                int C = 3;
                int nHeight, nWidth;
                file >> nWidth >> nHeight;

                float scale;
                file >> scale;                        // I noticed that scale is -1
                scale = fabs(scale);                // so here scale is 1.0

                CCustomBitmap image(nWidth, nHeight, C);

                for (int h = 0; h < nHeight; ++h)
                {
                        for (int w = 0; w < nWidth; ++w)
                        {
                                for (int c = 0; c < C; ++c)
                                {
                                        float x;
                                        file.read((char*)&x, sizeof(float));
                                        image[((nHeight - 1 - h) * nWidth + w) * C + c] = x * scale;  // scale is 1, so image[((nHeight - 1 - h) * nWidth + w) * C + c] = x is enough here
                                }
                        }
                }

                return image;
        }

---

but CCustomBitmap:: data is populated on 3 dimension array somehow ... the problem is that I don't know how to populate this CCustomBitmap:: data which has 3 d array from CImage, which has a 2 dimension array GetPixel(w, h). I don't have any extra-information about that variable, channels.

Because I am stuck here, any opinion/hint/solution will be very valuable !!! Thank you.