opengl.py

"""
    The OpenGL specification doesn't allow you to create a context without a window,
    since it needs the pixel format that you set into the device context.
    Actually, it is necessary to have a window handler to create a "traditional" rendering context.
    It is used to fetch OpenGL information and extensions availability.
    Once you got that information, you can destroy the render context and release the "dummy" window.
    So, in this code, the window is created, the context is set to this window,
    the image result is saved to an output image file and, then, this window is released.
"""


# import glfw
import OpenGL
import ctypes
import ctypes.util
# from lucid.misc.gl.glcontext import create_opengl_context
# from lib.glcontext import create_opengl_context
import glfw
from OpenGL.GL import *
import OpenGL.GL.shaders
import numpy
from PIL import Image
import base64
from io import BytesIO
from utils.settings import set_options
from pyvirtualdisplay import Display


def image_enhance(image, exposure, saturation, contrast, brightness, gamma, shadows, highlights, whites, blacks,
         clarity, temperature, sharpness):
    # create_opengl_context((image.width,image.height))
    # Initialize glfw
    disp = Display()
    disp.start()

    if not glfw.init():
        print('error in init')
        return

    # Create window
    # Size (1, 1) for show nothing in window
    glfw.window_hint(glfw.VISIBLE, False)
    window = glfw.create_window(1, 1, "My OpenGL window", None, None)
    # window = glfw.create_window(800, 600, "My OpenGL window", None, None)

    # Terminate if any issue
    if not window:
        print('error in window')
        glfw.terminate()
        return

    # Set context to window
    glfw.make_context_current(window)
    disp.stop()

    #

    # Initial data
    # Positions, colors, texture coordinates
    '''
    #           positions        colors          texture coords
    quad = [   -0.5, -0.5, 0.0,  1.0, 0.0, 0.0,  0.0, 0.0,
                0.5, -0.5, 0.0,  0.0, 1.0, 0.0,  1.0, 0.0,
                0.5,  0.5, 0.0,  0.0, 0.0, 1.0,  1.0, 1.0,
               -0.5,  0.5, 0.0,  1.0, 1.0, 1.0,  0.0, 1.0]
    '''
    #       positions      colors       texture coords
    quad = [-1., -1.,  0., 0.,
            1., -1.,  1., 0.,
            1.,  1.,  1., 1.,
            -1.,  1.,  0., 1.]
    quad = numpy.array(quad, dtype=numpy.float32)

    # Vertices indices order
    indices = [0, 1, 2,
               2, 3, 0]
    indices = numpy.array(indices, dtype=numpy.uint32)

    # print(quad.itemsize * len(quad))
    # print(indices.itemsize * len(indices))
    # print(quad.itemsize * 8)

    #

    # Vertex shader
    vertex_shader = """
    attribute vec4 a_position;
    attribute vec4 a_color;
    attribute vec2 a_texCoord;
    varying vec2 v_texCoord;
    varying vec4 v_color;

    void main() {
    gl_Position = a_position;
    v_texCoord = a_texCoord;
    v_color = vec4(a_color.rgb * a_color.a, a_color.a);
    }
    """

    # Fragment shader
    fragment_shader = """
    varying vec2 v_texCoord;
    uniform sampler2D u_image;

    uniform float u_gamma;
    uniform float u_shadows;
    uniform float u_highlights;
    uniform float u_whites;
    uniform float u_blacks;

    uniform float u_clarity;


    uniform mat4 u_colorMatrix;
    uniform vec4 u_colorOffset;

    uniform vec2 u_pixelDimension;

    uniform mat4 u_clarityMatrix;
    uniform vec4 u_clarityOffset;

    uniform float u_temperature;
    uniform float u_sharpness;


    const vec3 warmFilter = vec3(0.93, 0.54, 0.0);

    const mat3 RGBtoYIQ = mat3(0.299, 0.587, 0.114, 0.596, -0.274, -0.322, 0.212, -0.523, 0.311);
    const mat3 YIQtoRGB = mat3(1.0, 0.956, 0.621, 1.0, -0.272, -0.647, 1.0, -1.105, 1.702);


    const float EPSILON = 0.0000001;

    vec4 unpremultiply(vec4 col) {
        col.rgb /= max(col.a, EPSILON);
        return col;
    }

    float calculateLuminance(vec3 rgb) {
        // This is the luminance calculation part of the RGB to HSL formular.
        vec4 p = mix(
            vec4(rgb.gb, 0.0, -1.0 / 3.0),
            vec4(rgb.bg, -1.0, 2.0 / 3.0),
            vec4(rgb.g < rgb.b)
        );

        vec4 q = mix(
            vec4(rgb.r, p.yzx),
            vec4(p.xyw, rgb.r),
            vec4(rgb.r < p.x)
        );

        float croma = q.x - min(q.w, q.y);
        float luminance = q.x - croma * 0.5;
        return luminance;
    }

    vec3 map(vec3 x, float in_min, float in_max, float out_min, float out_max){
    return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
    }

    void main() {

    vec4 color = clamp(texture2D(u_image, v_texCoord), 0.0, 1.0);
    color.rgb /= max(color.a, EPSILON); // Revert premultiplied alpha

    // Apply gamma
    if (u_gamma != 1.0) {
        color.rgb = pow(color.rgb, vec3(1.0 / max(u_gamma, EPSILON)));
    }

    // Apply shadows and highlights
    float luminance = calculateLuminance(color.rgb);

    float shadow = u_shadows >= 0.0
        ? clamp(
            pow(luminance, 1.0 / (u_shadows + 1.0))
            + pow(luminance, 2.0 / (u_shadows + 1.0)) * -0.76
            - luminance
        , 0.0, max(u_shadows, 1.0))
        : -clamp(
            pow(luminance, 1.0 / (-u_shadows + 1.0))
            + pow(luminance, 2.0 / (-u_shadows + 1.0)) * -0.76
            - luminance
        , 0.0, max(-u_shadows, 1.0));

    float highlight = u_highlights < 0.0
        ? clamp(
            1.0
            - pow(1.0 - luminance, 1.0 / (1.0 - u_highlights))
            - pow(1.0 - luminance, 2.0 / (1.0 - u_highlights)) * -0.8
            - luminance
        , -1.0, 0.0)
        : -clamp(
            1.0
            - pow(1.0 - luminance, 1.0 / (1.0 + u_highlights))
            - pow(1.0 - luminance, 2.0 / (1.0 + u_highlights)) * -0.8
            - luminance
        , -1.0, 0.0);

    // Bright color need more contrast and dark color need more brightness.
    // This is to keep saturatation because the color information of a dark colors is lost.
    float shadowContrast   = shadow * luminance * luminance;
    float shadowBrightness = shadow - shadowContrast;

    float offset = luminance + shadowContrast + highlight;
    color.rgb = clamp(offset * ((color.rgb + shadowBrightness) / max(luminance, EPSILON)), 0.0, 1.0);
    
    // Apply Color Matrix
    color.rgb = clamp(color * u_colorMatrix + u_colorOffset, 0.0, 1.0).rgb;
    color.rgb = map(color.rgb, 0.0, 1.0, u_blacks / 2.0, 1.0 + u_whites / 2.0);
    color = clamp(color, 0.0, 1.0);
    color.rgb *= color.a; // Reset premultiplied alpha

    if (u_clarity != 0.0) {
        color = unpremultiply(color);

        // L = Left, R = Right, C = Center, T = Top, B = Bottom
        vec4 colLB = texture2D(u_image, v_texCoord + vec2(-u_pixelDimension.x, -u_pixelDimension.y));
        vec4 colLC = texture2D(u_image, v_texCoord + vec2(-u_pixelDimension.x,                 0.0));
        vec4 colLT = texture2D(u_image, v_texCoord + vec2(-u_pixelDimension.x,  u_pixelDimension.y));

        vec4 colCL = texture2D(u_image, v_texCoord + vec2(                0.0, -u_pixelDimension.y));
        vec4 colCR = texture2D(u_image, v_texCoord + vec2(                0.0,  u_pixelDimension.y));
        
        vec4 colRB = texture2D(u_image, v_texCoord + vec2( u_pixelDimension.x, -u_pixelDimension.y));
        vec4 colRC = texture2D(u_image, v_texCoord + vec2( u_pixelDimension.x,                 0.0));
        vec4 colRT = texture2D(u_image, v_texCoord + vec2( u_pixelDimension.x,  u_pixelDimension.y));

        vec4 mergedColor = color;
        mergedColor.rgb += unpremultiply(colLB).rgb + unpremultiply(colLC).rgb + unpremultiply(colLT).rgb;
        mergedColor.rgb += unpremultiply(colCL).rgb + unpremultiply(colCR).rgb;
        mergedColor.rgb += unpremultiply(colRB).rgb + unpremultiply(colRC).rgb + unpremultiply(colRT).rgb;

        mergedColor /= 9.0;

        float grayValue = clamp(color.r * 0.3 + color.g * 0.59 + color.b * 0.1, 0.111111, 0.999999);
        // 1.0 and 0.0 result in white not black, therefore we clamp

        // Here we create a function that will map values below 0.1 to 0. Values above 0.2 will be mapped to 1,
        // and for values between 0.1 and 0.2 it will produce a gradient.
        // The funtion is mirror at 0.5, meaning values between 0.8 and 0.9 will result in a decending gradient.
        // And values above 0.9 will be mapped to 0.
        float frequenceFactor = min(smoothstep(1.0 - grayValue, 0.0, 0.11), smoothstep(grayValue, 0.0, 0.11));

        // here we apply the high pass filter. Its strength is determined by the uniform ,
        // and the frequence factor. That means the only the mid tones are affected by this filter.
        // Clarity input is ranging from -1 to 1. But we want to strengthen the effect.
        // Therefore we see this little magic number '3.7'.
        color.rgb = clamp(color + clamp((color - mergedColor) * u_clarity * 3.7 * frequenceFactor, 0.0, 10.0), 0.0, 1.0).rgb;

        // apply exposure but only to the mid tones.
        color.rgb = color.rgb * pow(2.0, u_clarity * 0.27 * frequenceFactor);

        // apply contrast and desaturation matrix
        color.rgb = clamp(color * u_colorMatrix + u_colorOffset, 0.0, 1.0).rgb;

        color.rgb *= color.a; // Premultiply alpha
        color = clamp(color, 0.0, 1.0);
    }


    if(u_temperature != 0.0){
        float temperature = u_temperature;
        const float tint = 0.0;
        vec4 source = color;

        source.rgb /= max(source.a, EPSILON);   // Revert premultiplied alpha

        vec3 yiq = RGBtoYIQ * source.rgb;
        yiq.b = clamp(yiq.b + tint*0.5226*0.1, -0.5226, 0.5226);
        vec3 rgb = YIQtoRGB * yiq;

        vec3 processed = mix(
        (1.0 - 2.0 * (1.0 - rgb) * (1.0 - warmFilter)),
        (2.0 * rgb * warmFilter),
        vec3(rgb.r < 0.5, rgb.g < 0.5, rgb.b < 0.5)
        );

        color = vec4(mix(rgb, processed, temperature), source.a);

        color.rgb *= color.a;   // Premultiply alpha again

    }

    if (u_sharpness != 0.0){
        float factor        = mix(0.2, -1.0, float(u_sharpness > 0.0));
        vec4 sharpenedColor = mix(0.2,  5.0, float(u_sharpness > 0.0)) * color;
    
        sharpenedColor += factor * clamp(texture2D(u_image, v_texCoord + u_pixelDimension * vec2(-1.0,  0.0)), 0.0, 1.0);
        sharpenedColor += factor * clamp(texture2D(u_image, v_texCoord + u_pixelDimension * vec2( 0.0, -1.0)), 0.0, 1.0);
        sharpenedColor += factor * clamp(texture2D(u_image, v_texCoord + u_pixelDimension * vec2( 0.0,  1.0)), 0.0, 1.0);
        sharpenedColor += factor * clamp(texture2D(u_image, v_texCoord + u_pixelDimension * vec2( 1.0,  0.0)), 0.0, 1.0);
    
        color.rgb /= max(color.a, EPSILON); // unpremultiply
        sharpenedColor.rgb /= max(sharpenedColor.a, EPSILON); // unpremultiply
    
        sharpenedColor = clamp(sharpenedColor, 0.0, 1.0);
    
        color = clamp(mix(color, sharpenedColor, abs(u_sharpness)), 0.0, 1.0);
        
        color = vec4(color.rgb * color.a, color.a); // premultiply

    }


    gl_FragColor = color;
    }

    """

    #

    # Compile shaders
    shader = OpenGL.GL.shaders.compileProgram(OpenGL.GL.shaders.compileShader(vertex_shader, GL_VERTEX_SHADER),
                                              OpenGL.GL.shaders.compileShader(fragment_shader, GL_FRAGMENT_SHADER))

    # VBO
    v_b_o = glGenBuffers(1)
    glBindBuffer(GL_ARRAY_BUFFER, v_b_o)
    glBufferData(GL_ARRAY_BUFFER, quad.itemsize *
                 len(quad), quad, GL_STATIC_DRAW)

    # EBO
    e_b_o = glGenBuffers(1)
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, e_b_o)
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, indices.itemsize *
                 len(indices), indices, GL_STATIC_DRAW)

    # Configure positions of initial data
    # Configure positions of initial data
    glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4 *
                          sizeof(GLfloat), ctypes.c_void_p(0))
    glEnableVertexAttribArray(0)

    # Configure texture coordinates of initial data
    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4 *
                          sizeof(GLfloat), ctypes.c_void_p(8))
    glEnableVertexAttribArray(1)

    # Texture
    texture = glGenTextures(1)
    # Bind texture
    glBindTexture(GL_TEXTURE_2D, texture)
    # Texture wrapping params
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE)
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE)
    # Texture filtering params
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR)
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST)

    #

    # Open image

    #
    # img_data = numpy.array(list(image.getdata()), numpy.uint8)
    #
    # flipped_image = image.transpose(Image.FLIP_TOP_BOTTOM)
    # img_data = flipped_image.convert("RGBA").tobytes()
    #
    img_data = image.convert("RGBA").tobytes()
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, image.width,
                 image.height, 0, GL_RGBA, GL_UNSIGNED_BYTE, img_data)
    # print(image.width, image.height)

    #

    # Create render buffer with size (image.width x image.height)
    rb_obj = glGenRenderbuffers(1)
    glBindRenderbuffer(GL_RENDERBUFFER, rb_obj)
    glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA, image.width, image.height)

    # Create frame buffer
    fb_obj = glGenFramebuffers(1)
    glBindFramebuffer(GL_FRAMEBUFFER, fb_obj)
    glFramebufferRenderbuffer(
        GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, rb_obj)

    # Check frame buffer (that simple buffer should not be an issue)
    status = glCheckFramebufferStatus(GL_FRAMEBUFFER)
    if status != GL_FRAMEBUFFER_COMPLETE:
        print("incomplete framebuffer object")

    #

    # Install program
    glUseProgram(shader)

    set_options(exposure, saturation, contrast, brightness, gamma, shadows, highlights, whites, blacks,
                clarity, temperature, sharpness, shader, image.width, image.height)

    # Bind framebuffer and set viewport size
    glBindFramebuffer(GL_FRAMEBUFFER, fb_obj)
    glViewport(0, 0, image.width, image.height)

    # Draw the quad which covers the entire viewport
    glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, None)

    #

    # PNG
    # Read the data and create the image
    image_buffer = glReadPixels(
        0, 0, image.width, image.height, GL_RGBA, GL_UNSIGNED_BYTE)
    image_out = numpy.frombuffer(image_buffer, dtype=numpy.uint8)
    image_out = image_out.reshape(image.height, image.width, 4)
    # glfw.terminate()
    img = Image.fromarray(image_out, 'RGBA')


    buffered = BytesIO()
    img.save(buffered, format="PNG")
    img_str = base64.b64encode(buffered.getvalue())

    return img_str



if __name__ == "__main__":
    image = Image.open("/Users/planningo/Downloads/download.jpeg")
    image_enhance(image, exposure=0, saturation=0, contrast=0, brightness=0, gamma=1, shadows=0,
         highlights=0, blacks=0, whites=0, clarity=0, temperature=-1, sharpness=1)