NotMyFault Posted November 30, 2021 Posted November 30, 2021 Hi, these are maybe multiple issues, but all in the same area: iPad is unable to create a new document with RGB/32 (you can convert from 16 to 32 after creating RGB/16) iPad is unable to export as png with RGB/32 (if you try you get RGB/16 instead) As this happens for new files, i don’t upload a test image. Quote Mac mini M1 A2348 | MBP M3 Windows 11 - AMD Ryzen 9 5900x - 32 GB RAM - Nvidia GTX 1080 LG34WK950U-W, calibrated to DCI-P3 with LG Calibration Studio / Spider 5 | Dell 27“ 4K iPad Air Gen 5 (2022) A2589 Special interest into procedural texture filter, edit alpha channel, RGB/16 and RGB/32 color formats, stacking, finding root causes for misbehaving files, finding creative solutions for unsolvable tasks, finding bugs in Apps. I use iPad screenshots and videos even in the Desktop section of the forum when I expect no relevant difference.
Dan C Posted December 1, 2021 Posted December 1, 2021 Hi @NotMyFault, Thanks for your report! I can confirm the first issue is already logged with our devs, I'll get this bumped now. Regarding the second report, this is the correct behaviour - both the Affinity desktop and iPad apps export PNG in 24bit + 8 bit alpha when transparency is present. I hope this helps Quote
walt.farrell Posted December 1, 2021 Posted December 1, 2021 26 minutes ago, Dan C said: both the Affinity desktop and iPad apps export PNG in 24bit + 8 bit alpha when transparency is present. That is fine for RGB/8 images, but the report was about RGB/32 images. Quote -- Walt Designer, Photo, and Publisher V1 and V2 at latest retail and beta releases PC: Desktop: Windows 11 Pro 23H2, 64GB memory, AMD Ryzen 9 5900 12-Core @ 3.00 GHz, NVIDIA GeForce RTX 3090 Laptop: Windows 11 Pro 23H2, 32GB memory, Intel Core i7-10750H @ 2.60GHz, Intel UHD Graphics Comet Lake GT2 and NVIDIA GeForce RTX 3070 Laptop GPU. Laptop 2: Windows 11 Pro 24H2, 16GB memory, Snapdragon(R) X Elite - X1E80100 - Qualcomm(R) Oryon(TM) 12 Core CPU 4.01 GHz, Qualcomm(R) Adreno(TM) X1-85 GPU iPad: iPad Pro M1, 12.9": iPadOS 18.3, Apple Pencil 2, Magic Keyboard Mac: 2023 M2 MacBook Air 15", 16GB memory, macOS Sequoia 15.0.1
NotMyFault Posted December 1, 2021 Author Posted December 1, 2021 12 minutes ago, walt.farrell said: That is fine for RGB/8 images, but the report was about RGB/32 images. It seems Dan C gave the correct answer (as almost every time). PNG actually does not support RGB/32, with or without alpha channel. I failed to check this before posting. https://en.wikipedia.org/wiki/Portable_Network_Graphics Pixel format[edit] PNG color type[9] Color type Channels Bits per channel 1 2 4 8 16 Indexed 1 1 2 4 8 Grayscale 1 1 2 4 8 16 Grayscale and alpha 2 16 32 Truecolor 3 24 48 Truecolor and alpha 4 32 64 Pixels in PNG images are numbers that may be either indices of sample data in the palette or the sample data itself. The palette is a separate table contained in the PLTE chunk. Sample data for a single pixelconsists of a tuple of between one and four numbers. Whether the pixel data represents palette indices or explicit sample values, the numbers are referred to as channels and every number in the image is encoded with an identical format. The permitted formats encode each number as an unsigned integer value using a fixed number of bits, referred to in the PNG specification as the bit depth. Notice that this is not the same as color depth, which is commonly used to refer to the total number of bits in each pixel, not each channel. The permitted bit depths are summarized in the table along with the total number of bits used for each pixel. Quote Mac mini M1 A2348 | MBP M3 Windows 11 - AMD Ryzen 9 5900x - 32 GB RAM - Nvidia GTX 1080 LG34WK950U-W, calibrated to DCI-P3 with LG Calibration Studio / Spider 5 | Dell 27“ 4K iPad Air Gen 5 (2022) A2589 Special interest into procedural texture filter, edit alpha channel, RGB/16 and RGB/32 color formats, stacking, finding root causes for misbehaving files, finding creative solutions for unsolvable tasks, finding bugs in Apps. I use iPad screenshots and videos even in the Desktop section of the forum when I expect no relevant difference.
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