srgb

OpenGL: Gamma corrected image doesn't appear linear

由 孤街浪徒 提交于 2019-12-12 09:39:05
问题 I'm using OpenGL for rendering, and when I write linear values to the default framebuffer (without any gamma correction) they appear linear on my monitor. This goes against everything I thought I knew about gamma correction (as explained here: http://gamedevelopment.tutsplus.com/articles/gamma-correction-and-why-it-matters--gamedev-14466 ). Without gamma correction, I would expect to see mid-range colors darkened non-linearly by my monitor. But here is what I actually see; first with no gamma

OpenCV strip sRGB profile when imdecode image Python

由 拥有回忆 提交于 2019-12-11 09:03:19
问题 I am reading in images which I fetch from the internet and then immediately read into OpenCV in python as below: # read in image as bytes from page image = page.raw_stream.read() frame = cv2.imdecode(np.asarray(bytearray(image)), 0) and I am getting the libpng warning: libpng warning: iCCP: known incorrect sRGB profile How can I strip the sRGB profile before imread? People are suggesting to do it via imagemagick on the png files before reading them but this is not possible for me. Is there no

Why do I get an sRGB framebuffer only when I'm setting a non-zero alpha size in SDL2?

由 匆匆过客 提交于 2019-12-10 14:26:25
问题 I'm trying to render the typical OpenGL color triangle in a gamma correct way by following this guide and consulting the SDL2 documentation on how to enable SRGB support on the default framebuffer. This is the code I've written, which draws the triangle: #include <SDL.h> // Header file generated with glLoadGen #include "gl_core_3_3.h" #include <cstdlib> void sdl_loop(SDL_Window* window); static const char* const vertexSource = R"( #version 330 in vec2 position; in vec3 color; out vec3 vs

OpenGL: Gamma corrected image doesn't appear linear

由 强颜欢笑 提交于 2019-12-10 04:59:31
问题 I'm using OpenGL for rendering, and when I write linear values to the default framebuffer (without any gamma correction) they appear linear on my monitor. This goes against everything I thought I knew about gamma correction (as explained here: http://gamedevelopment.tutsplus.com/articles/gamma-correction-and-why-it-matters--gamedev-14466 ). Without gamma correction, I would expect to see mid-range colors darkened non-linearly by my monitor. But here is what I actually see; first with no gamma

SRGB-aware image resize in Pillow

由 a 夏天 提交于 2019-12-09 17:50:21
问题 Pillow's basic Image.resize function doesn't appear to have any options for SRGB-aware filtering. Is there a way to do SRGB-aware resizing in Pillow? I could do it manually by converting the image to float and applying the SRGB transforms myself...but I'm hoping there's a built-in way. 回答1: I ended up implementing sRGB-aware resize myself using the following routine. It takes an 8-bit RGB image and a target size and resampling filter. from PIL import Image import numpy as np def SRGBResize(im

SRGB-aware image resize in Pillow

由 情到浓时终转凉″ 提交于 2019-12-04 05:59:31
Pillow's basic Image.resize function doesn't appear to have any options for SRGB-aware filtering. Is there a way to do SRGB-aware resizing in Pillow? I could do it manually by converting the image to float and applying the SRGB transforms myself...but I'm hoping there's a built-in way. I ended up implementing sRGB-aware resize myself using the following routine. It takes an 8-bit RGB image and a target size and resampling filter. from PIL import Image import numpy as np def SRGBResize(im, size, filter): # Convert to numpy array of float arr = np.array(im, dtype=np.float32) / 255.0 # Convert

iccp:Not recognizing known sRGB profile that has been edited

由 风流意气都作罢 提交于 2019-12-03 09:33:52
The following warning keeps arising in my Xamarin cross platform PCL project: iccp:Not recognizing known sRGB profile that has been edited What should I do ? If you have image magick installed http://www.imagemagick.org/script/command-line-processing.php find . -name "*.png" -print -exec convert "{}" "{}" ";" cleaned up the files, and made them smaller in the process. I had the same problem with Android studio. Just clean the project and it should work. I found a workaround that may help. I downloaded the ImageOptim software: https://imageoptim.com/ (Free) and went to the folder Xamarin

Color spaces, gamma and image enhancement

由 ◇◆丶佛笑我妖孽 提交于 2019-12-03 03:20:12
问题 Color space . Well, everybody knows about RGB: three values normalized in the range [0.0,1.0], which have the meaning of the intensity of the color components Red Green Blue; this intensity is meant as linear, isn't? Gamma . As far I can understand, gamma is a function which maps RGB color components to another value. Googling on this, I've seen linear functions and non linear functions... Linear functions seems to scale RGB components, so it seems to tune image brightness; non linear

Color spaces, gamma and image enhancement

由 孤者浪人 提交于 2019-12-02 16:50:48
Color space . Well, everybody knows about RGB: three values normalized in the range [0.0,1.0], which have the meaning of the intensity of the color components Red Green Blue; this intensity is meant as linear, isn't? Gamma . As far I can understand, gamma is a function which maps RGB color components to another value. Googling on this, I've seen linear functions and non linear functions... Linear functions seems to scale RGB components, so it seems to tune image brightness; non linear functions seems to "decompress" darker/lighter components. Now, I'm starting to implement an image viewer,

When to call glEnable(GL_FRAMEBUFFER_SRGB)?

由 爷，独闯天下 提交于 2019-11-27 20:55:50
问题 I have a rendering system where I draw to an FBO with a multisampled renderbuffer, then blit it to another FBO with a texture in order to resolve the samples in order to read off the texture to perform post-processing shading while drawing to the backbuffer (FBO index 0). Now I'd like to get some correct sRGB output... The problem is the behavior of the program is rather inconsistent between when I run it on OS X and Windows and this also changes depending on the machine: On Windows with the
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